paul@102 | 1 | imip-agent
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paul@102 | 2 | ==========
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paul@102 | 3 |
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paul@102 | 4 | This software implements an agent that can interpret e-mail messages
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paul@102 | 5 | containing calendar information, maintain availability records for scheduling
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paul@102 | 6 | participants, act on behalf of resources and other entities that need to
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paul@102 | 7 | participate in scheduling, and support user interfaces for end-users whose
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paul@102 | 8 | e-mail programs do not understand calendar data.
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paul@102 | 9 |
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paul@102 | 10 | Getting Started
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paul@102 | 11 | ===============
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paul@102 | 12 |
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paul@102 | 13 | Eventually, this information should be incorporated into packages for various
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paul@102 | 14 | operating system distributions, and these instructions should be largely
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paul@102 | 15 | superfluous for most users.
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paul@102 | 16 |
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paul@102 | 17 | System User and Filesystem Access
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paul@732 | 18 | =================================
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paul@102 | 19 |
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paul@731 | 20 | The data handled by imip-agent needs to be accessible to other software,
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paul@731 | 21 | notably mail handling software and Web server software. Two approaches are
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paul@731 | 22 | described here: LMTP delivery and local SMTP delivery.
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paul@731 | 23 |
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paul@731 | 24 | LMTP Delivery
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paul@731 | 25 | -------------
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paul@731 | 26 |
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paul@731 | 27 | Here, imip-agent's programs run in a way that permits LMTP delivery (requiring
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paul@731 | 28 | suitable local privileges to communicate with the mail storage solution)
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paul@731 | 29 | whilst allowing the Web server to read data written by those programs.
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paul@731 | 30 |
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paul@209 | 31 | A system group needs to be created for LMTP delivery and for certain users to
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paul@209 | 32 | share resources:
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paul@209 | 33 |
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paul@209 | 34 | addgroup lmtp
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paul@209 | 35 |
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paul@209 | 36 | This group should be employed for LMTP delivery by systems like Cyrus and
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paul@209 | 37 | Dovecot. See the section on configuring mail systems for delivery for more
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paul@209 | 38 | information.
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paul@209 | 39 |
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paul@102 | 40 | A system user needs to be created and to belong to certain groups in order to
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paul@102 | 41 | deliver messages to mail stores and to publish resources on the Web:
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paul@102 | 42 |
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paul@102 | 43 | useradd -d /var/lib/imip-agent -m -U -G lmtp,www-data -r imip-agent
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paul@102 | 44 |
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paul@209 | 45 | Store details and published resources need to be accessible by the imip-agent
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paul@209 | 46 | and www-data users. Thus, www-data also needs to belong to the lmtp group:
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paul@102 | 47 |
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paul@209 | 48 | adduser www-data lmtp
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paul@209 | 49 |
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paul@634 | 50 | Stored and published data is then initialised using the tools/init.sh script.
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paul@634 | 51 | The script employs the setgid flag on the directories initialised for stored
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paul@634 | 52 | and published data so that new files and directories have the appropriate
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paul@634 | 53 | group associated with them.
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paul@102 | 54 |
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paul@731 | 55 | It should be possible to omit all arguments to the init.sh script, but it is
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paul@731 | 56 | also worth reading the help message:
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paul@731 | 57 |
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paul@731 | 58 | tools/init.sh --help
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paul@731 | 59 |
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paul@634 | 60 | Fixing ownership can be done using the tools/fix.sh script, in case some form
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paul@634 | 61 | of modification has altered the ownership or membership of the created files
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paul@634 | 62 | and directories.
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paul@102 | 63 |
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paul@731 | 64 | Local SMTP Delivery
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paul@731 | 65 | -------------------
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paul@731 | 66 |
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paul@731 | 67 | Here, imip-agent's programs run in a way that permits local SMTP delivery
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paul@731 | 68 | (which merely needs the ability to connect to a local network service) whilst
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paul@731 | 69 | allowing the Web server to read data written by those programs.
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paul@731 | 70 |
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paul@731 | 71 | A system user needs to be created and to belong to certain groups in order to
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paul@731 | 72 | deliver messages to mail stores and to publish resources on the Web:
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paul@731 | 73 |
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paul@731 | 74 | useradd -d /var/lib/imip-agent -m -U -G www-data -r imip-agent
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paul@731 | 75 |
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paul@731 | 76 | Again, the tools/init.sh script will initialise directories for stored and
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paul@891 | 77 | published data. The tools/config.sh script should be edited and the group
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paul@891 | 78 | redefined as follows:
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paul@731 | 79 |
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paul@891 | 80 | IMIP_AGENT_GROUP=www-data
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paul@891 | 81 |
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paul@891 | 82 | If already installed, the /etc/imip-agent/config.sh script should be edited
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paul@891 | 83 | instead.
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paul@731 | 84 |
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paul@102 | 85 | Installing the Software
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paul@732 | 86 | =======================
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paul@102 | 87 |
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paul@102 | 88 | The tools/install.sh script should install the software in appropriate
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paul@175 | 89 | locations. See the prerequisites below for other software that will be
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paul@175 | 90 | required.
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paul@102 | 91 |
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paul@102 | 92 | Configuring Other Software
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paul@732 | 93 | ==========================
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paul@102 | 94 |
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paul@102 | 95 | The conf directory contains subdirectories for different systems:
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paul@102 | 96 |
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paul@102 | 97 | apache Apache 2 site configuration for publishing resources
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paul@670 | 98 | cron Cron command scheduling for free/busy updates
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paul@102 | 99 | exim Exim 4 routing and transport configuration
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paul@102 | 100 | postfix Postfix routing and transport configuration
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paul@102 | 101 |
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paul@102 | 102 | Either Exim or Postfix can be chosen as a mail system supporting the agent.
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paul@143 | 103 |
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paul@143 | 104 | Configuring Mail Systems for the Agent
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paul@143 | 105 | --------------------------------------
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paul@143 | 106 |
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paul@143 | 107 | The essential aspect of mail system configuration involves mail transports and
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paul@143 | 108 | the integration of agent programs into the mail processing pipeline. Thus, the
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paul@143 | 109 | following files are of particular interest:
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paul@143 | 110 |
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paul@175 | 111 | For Exim (in conf/exim)...
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paul@143 | 112 |
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paul@175 | 113 | 30_exim4-config_people Integration of agent programs
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paul@175 | 114 | 30_exim4-config_people_outgoing ...
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paul@175 | 115 | 30_exim4-config_resources ...
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paul@143 | 116 |
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paul@175 | 117 | For Postfix (in conf/postfix)...
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paul@143 | 118 |
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paul@175 | 119 | master.cf.items Integration of agent programs (for
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paul@175 | 120 | inclusion in master.cf)
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paul@175 | 121 | transport Configuration of agent transports
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paul@175 | 122 | virtual Configuration of outgoing mail routing
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paul@143 | 123 |
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paul@143 | 124 | Such files need adjusting for the deployment environment so that, for example,
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paul@143 | 125 | the example.com domain would be replaced with a suitable value.
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paul@143 | 126 |
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paul@900 | 127 | If local SMTP delivery is being used, the 30_exim4-config_people file (in
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paul@900 | 128 | conf/exim) or the master.cf.items file (in conf/postfix) will need adjusting.
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paul@900 | 129 | Where LMTP_SOCKET is employed, a suitable filesystem path is required; where
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paul@900 | 130 | the lmtp system group is employed, it may be replaced with a different group.
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paul@900 | 131 | See below for a discussion of LMTP and mail delivery.
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paul@891 | 132 |
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paul@143 | 133 | Configuring Mail Systems for Mail Recipients
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paul@143 | 134 | --------------------------------------------
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paul@143 | 135 |
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paul@143 | 136 | The software should operate independently of the way mail recipients are
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paul@143 | 137 | identified in any given mail system, and thus does not dictate things such as
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paul@143 | 138 | routing or account querying. However, example configuration files are provided
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paul@143 | 139 | that demonstrate the use of LDAP to identify mail recipients:
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paul@143 | 140 |
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paul@900 | 141 |
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paul@890 | 142 | For Exim with LDAP (in conf/exim/ldap)...
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paul@143 | 143 |
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paul@899 | 144 | 010_exim4-config_ldap_people_outgoing Defines recipients and outgoing
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paul@175 | 145 | mail routing
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paul@899 | 146 | 020_exim4-config_ldap_people ...
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paul@899 | 147 | 020_exim4-config_ldap_resources ...
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paul@899 | 148 | 020_exim4-config_ldap_people_outgoing_recipients
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paul@143 | 149 |
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paul@900 | 150 |
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paul@175 | 151 | For Postfix with LDAP (in conf/postfix/ldap)...
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paul@143 | 152 |
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paul@175 | 153 | main.cf.example Defines recipients and outgoing
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paul@175 | 154 | mail routing (for inclusion in
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paul@175 | 155 | main.cf)
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paul@175 | 156 |
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paul@177 | 157 | virtual_alias_maps_people.cf Defines recipients and outgoing
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paul@177 | 158 | virtual_alias_maps_people_outgoing.cf mail routing
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paul@176 | 159 | virtual_alias_maps_resources.cf ...
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paul@143 | 160 |
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paul@900 | 161 |
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paul@664 | 162 | Since the use of LDAP can be somewhat challenging and also excessive in some
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paul@664 | 163 | situations, examples of maintaining recipient information using a simpler
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paul@900 | 164 | approach are provided.
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paul@900 | 165 |
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paul@900 | 166 | In this simpler environment, recipient details must be manually edited in the
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paul@900 | 167 | virtual identity files, but this permits a very transparent way of
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paul@900 | 168 | administering the system.
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paul@900 | 169 |
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paul@664 | 170 |
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paul@890 | 171 | For Exim without LDAP (in conf/exim/simple)...
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paul@890 | 172 |
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paul@890 | 173 | 010_exim4-config_people_outgoing Defines recipients and outgoing
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paul@890 | 174 | mail routing
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paul@899 | 175 | 020_exim4-config_people ...
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paul@899 | 176 | 020_exim4-config_resources ...
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paul@899 | 177 | 020_exim4-config_people_outgoing_recipients
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paul@890 | 178 |
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paul@890 | 179 | virtual_people Defines recipient identities
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paul@899 | 180 | virtual_people_outgoing_recipients belonging to known domains
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paul@899 | 181 | virtual_resources ...
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paul@890 | 182 |
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paul@890 | 183 | virtual_domains Defines recipient domains
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paul@899 | 184 |
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paul@900 | 185 | To add support for delivery to local mailboxes, the following additional file
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paul@900 | 186 | is provided as an example:
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paul@899 | 187 |
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paul@899 | 188 | virtual_people_local Defines recipients and local users
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paul@890 | 189 |
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paul@900 | 190 | And to route bounced messages back to the generic calendar address, an
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paul@900 | 191 | addition to the /etc/aliases file is provided:
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paul@900 | 192 |
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paul@900 | 193 | aliases.example Routes calendar to root
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paul@900 | 194 |
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paul@900 | 195 |
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paul@177 | 196 | For Postfix without LDAP (in conf/postfix/simple)...
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paul@177 | 197 |
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paul@177 | 198 | main.cf.example Defines recipients and outgoing
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paul@177 | 199 | mail routing (for inclusion in
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paul@177 | 200 | main.cf)
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paul@177 | 201 |
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paul@664 | 202 | virtual_alias_maps Defines recipients and outgoing
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paul@177 | 203 | virtual_alias_maps_people_outgoing mail routing
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paul@177 | 204 |
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paul@900 | 205 | To add support for delivery to local mailboxes, the following alternative to
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paul@900 | 206 | virtual_alias_maps is provided as an example:
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paul@666 | 207 |
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paul@666 | 208 | virtual_alias_maps_local Defines recipients and local users
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paul@664 | 209 |
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paul@900 | 210 |
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paul@664 | 211 | Naturally, the above recipient identification configuration examples can be
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paul@664 | 212 | disregarded in favour of other ways of defining mail recipients, subject to
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paul@664 | 213 | the needs of any given environment.
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paul@143 | 214 |
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paul@144 | 215 | LDAP Representations for Mail Recipients
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paul@144 | 216 | ----------------------------------------
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paul@144 | 217 |
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paul@144 | 218 | Relevant LDAP resources for structuring recipient information include the
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paul@144 | 219 | following:
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paul@144 | 220 |
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paul@175 | 221 | RFC 4524 Defines the mail attribute
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paul@175 | 222 | http://tools.ietf.org/html/rfc4524
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paul@175 | 223 |
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paul@175 | 224 | RFC 2798 Defines the inetOrgPerson object
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paul@175 | 225 | http://tools.ietf.org/html/rfc2798 class
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paul@175 | 226 |
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paul@175 | 227 | RFC 2739 Defines the calEntry object class
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paul@175 | 228 | https://tools.ietf.org/html/rfc2739 supporting calFBURL
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paul@144 | 229 |
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paul@144 | 230 | An additional draft RFC describes the mailRecipient object class:
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paul@144 | 231 |
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paul@144 | 232 | https://tools.ietf.org/html/draft-lachman-ldap-mail-routing-03
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paul@144 | 233 |
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paul@144 | 234 | Resource schemas for LDAP are not effectively standardised for the purposes of
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paul@145 | 235 | this software. A useful object class, inetResource, was defined for the
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paul@145 | 236 | iPlanet Calendar Server:
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paul@145 | 237 |
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paul@145 | 238 | http://docs.oracle.com/cd/E19566-01/819-4437/6n6jckqrf/index.html#anocg
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paul@145 | 239 | http://docs.oracle.com/cd/E19566-01/819-4437/6n6jckqr8/index.html
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paul@145 | 240 |
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paul@145 | 241 | Although Kolab maintains notions of resources, they are tied up with the
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paul@145 | 242 | notion of a shared folder and the kolabSharedFolder object class, although the
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paul@145 | 243 | mailRecipient object class is employed by resources in Kolab.
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paul@144 | 244 |
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paul@143 | 245 | Configuring Mail Systems for Mail Delivery
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paul@143 | 246 | ------------------------------------------
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paul@143 | 247 |
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paul@143 | 248 | The agent software assumes that delivery of mail to recipients may be
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paul@900 | 249 | performed either using local SMTP or by using LMTP to a suitable mailbox
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paul@900 | 250 | provider.
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paul@900 | 251 |
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paul@900 | 252 | If employing local SMTP, the burden of routing messages to suitable storage
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paul@900 | 253 | becomes a configuration problem within the mail system itself, but given that
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paul@900 | 254 | routing to local system users is typically supported "out of the box", this
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paul@900 | 255 | can provide a usable solution with minimal effort.
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paul@900 | 256 |
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paul@900 | 257 | By using LMTP from the agent software, the issue of configuring the mail
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paul@900 | 258 | system to integrate with storage solutions is avoided, but then those
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paul@900 | 259 | solutions must expose their LMTP interface appropriately.
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paul@900 | 260 |
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paul@900 | 261 | Although this topic is largely beyond the scope of this document, systems such
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paul@900 | 262 | as Cyrus and Dovecot can be configured to provide a Unix domain socket
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paul@900 | 263 | offering support for LMTP connections.
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paul@133 | 264 |
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paul@209 | 265 | For Cyrus, the following bug report is pertinent:
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paul@209 | 266 |
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paul@209 | 267 | https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=494746
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paul@209 | 268 |
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paul@209 | 269 | A permanent change in permissions on the Cyrus LMTP socket is therefore
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paul@209 | 270 | required to make delivery available to the lmtp group:
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paul@209 | 271 |
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paul@209 | 272 | dpkg-statoverride --force --update --add \
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paul@209 | 273 | cyrus lmtp 750 /var/run/cyrus/socket
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paul@209 | 274 |
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paul@670 | 275 | Configuring Cron for Free/Busy Updates
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paul@670 | 276 | --------------------------------------
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paul@670 | 277 |
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paul@670 | 278 | The periods occupied by recurring events are not expanded beyond a certain
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paul@670 | 279 | window of time by imip-agent. As a consequence, free/busy collections need to
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paul@670 | 280 | be progressively expanded over time to include periods occupied by such events
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paul@670 | 281 | that were not previously recorded in those collections.
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paul@670 | 282 |
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paul@670 | 283 | The conf/cron/cron.daily/imip-agent file contains commands that update
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paul@670 | 284 | free/busy collections for all known users, and this should be copied to the
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paul@670 | 285 | appropriate destination. For example:
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paul@670 | 286 |
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paul@670 | 287 | cp conf/cron/cron.daily/imip-agent /etc/cron.daily/
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paul@670 | 288 |
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paul@670 | 289 | Where frequency-specific directories are not supported by cron on a system, a
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paul@670 | 290 | crontab entry of the appropriate format is required instead.
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paul@670 | 291 |
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paul@748 | 292 | Configuring Web Servers for Free/Busy Publishing
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paul@748 | 293 | ------------------------------------------------
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paul@748 | 294 |
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paul@748 | 295 | Each user may request the publishing of their free/busy information by
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paul@748 | 296 | configuring certain settings. The conf/apache/imip-agent.conf file provides a
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paul@748 | 297 | configuration file for deployment with the Apache Web server software that
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paul@748 | 298 | exposes a directory for Web publishing containing the published free/busy
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paul@748 | 299 | information.
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paul@748 | 300 |
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paul@748 | 301 | Access to free/busy information may not be moderated, but Web server
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paul@748 | 302 | directives can be introduced to impose access controls. Mail programs that
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paul@748 | 303 | wish to consult the free/busy information may have problems in dealing with
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paul@748 | 304 | authentication mechanisms, however, and it may be regarded as acceptable in
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paul@748 | 305 | certain environments to expose such information publicly or with
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paul@748 | 306 | network-specific access constraints.
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paul@748 | 307 |
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paul@748 | 308 | Configuring Web Servers for the Calendar Management Interface
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paul@748 | 309 | -------------------------------------------------------------
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paul@748 | 310 |
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paul@748 | 311 | A calendar management interface is provided to allow users to view and
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paul@748 | 312 | interact with their calendars through the Web. The
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paul@748 | 313 | conf/apache/imip-manager.conf file provides a configuration file for
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paul@748 | 314 | deployment with the Apache Web server software that enables this interface.
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paul@748 | 315 |
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paul@748 | 316 | Since such access to calendars should only be performed by identified
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paul@748 | 317 | users, access controls are suggested in the configuration file.
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paul@748 | 318 |
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paul@133 | 319 | Prerequisites
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paul@732 | 320 | =============
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paul@133 | 321 |
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paul@133 | 322 | Depending on the mail transport agent (MTA) chosen, the following packages are
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paul@133 | 323 | required for this software to work on Debian systems:
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paul@133 | 324 |
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paul@133 | 325 | Exim: exim4-daemon-heavy
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paul@133 | 326 | Postfix: postfix postfix-ldap
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paul@149 | 327 |
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paul@175 | 328 | The software itself requires the following packages:
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paul@175 | 329 |
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paul@890 | 330 | Python: python
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paul@175 | 331 | pytz: python-tz
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paul@175 | 332 |
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paul@900 | 333 | To update free/busy details periodically, the following software is
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paul@900 | 334 | recommended:
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paul@900 | 335 |
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paul@900 | 336 | Cron: cron
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paul@900 | 337 |
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paul@149 | 338 | The management Web interface requires the following packages:
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paul@149 | 339 |
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paul@890 | 340 | Apache: apache2
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paul@149 | 341 | Babel: python-babel
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paul@890 | 342 |
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paul@890 | 343 | Although not necessarily within the scope of the deployment of this software,
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paul@890 | 344 | the following mail storage solutions would be used to receive and hold
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paul@890 | 345 | messages:
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paul@890 | 346 |
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paul@890 | 347 | Cyrus: cyrus-imapd
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paul@890 | 348 | Dovecot: dovecot-imapd dovecot-ldap dovecot-lmtpd
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