125 lines
4.2 KiB
Markdown
125 lines
4.2 KiB
Markdown
E-MailRelay Readme
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==================
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Abstract
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--------
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E-MailRelay is an e-mail store-and-forward message transfer agent and proxy
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server. It runs on Unix-like operating systems (including Linux and Mac OS X),
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and on Windows.
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E-MailRelay does three things: it stores any incoming e-mail messages that
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it receives, it forwards e-mail messages on to another remote e-mail server,
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and it serves up stored e-mail messages to local e-mail reader programs. More
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technically, it acts as a [SMTP][] storage daemon, a SMTP forwarding agent, and
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a POP3 server.
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Whenever an e-mail message is received it can be passed through a user-defined
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program, such as a spam filter, which can drop, re-address or edit messages as
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they pass through.
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E-MailRelay uses the same non-blocking i/o model as Squid and nginx giving
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excellent scalability and resource usage.
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C++ source code is available and distribution is permitted under the GNU
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General Public License V3.
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Quick start
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-----------
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To use E-MailRelay in store-and-forward mode use the `--as-server` option to
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start the storage daemon in the background, and then do delivery of spooled
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messages by running with the `--as-client` option.
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For example, to start a storage daemon listening on port 587 use a command
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like this:
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emailrelay --as-server --port 587 --spool-dir /tmp
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And then to forward the spooled mail to `smtp.example.com` run something
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like this:
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emailrelay --as-client smtp.example.com:25 --spool-dir /tmp
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To get behaviour more like a proxy you can add the `--poll` and `--forward-to`
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options so that messages are forwarded continuously rather than on-demand.
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This example starts a store-and-forward server that forwards spooled-up e-mail
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every minute:
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emailrelay --as-server --poll 60 --forward-to smtp.example.com:25
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Or for a proxy server that forwards each message soon after it has been
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received, you can use `--as-proxy` or add `--forward-on-disconnect`:
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emailrelay --as-server --forward-on-disconnect --forward-to smtp.example.com:25
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To edit or filter e-mail as it passes through the proxy specify your filter
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program with the `--filter` option, something like this:
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emailrelay --as-proxy smtp.example.com:25 --filter addsig.js
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To run E-MailRelay as a [POP][] server without SMTP use `--pop` and `--no-smtp`:
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emailrelay --pop --no-smtp --log --close-stderr
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The `emailrelay-submit` utility can be used to put messages straight into the
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spool directory so that the POP clients can fetch them.
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By default E-MailRelay will always reject connections from remote networks. To
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allow connections from anywhere use the `--remote-clients` option, but please
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check your firewall settings to make sure this cannot be exploited by spammers.
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For more information on the command-line options refer to the reference guide
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or run:
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emailrelay --help --verbose
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Packages
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--------
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To install on Linux from a RPM or DEB package:
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sudo $SHELL # or 'su'
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rpm -i emailrelay*.rpm # if RPM
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dpkg -i emailrelay*.deb # if DEB
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If your Linux system uses `systemd` then you should check the E-MailRelay
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configuration file `/etc/emailrelay.conf` is as you want it and then run:
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systemctl enable emailrelay
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systemctl start emailrelay
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systemctl status emailrelay
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On other systems try these commands:
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cp /usr/lib/emailrelay/init/emailrelay /etc/init.d/
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update-rc.d emailrelay enable || rc-update add emailrelay
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invoke-rc.d emailrelay start || service emailrelay start
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tail /var/log/messages /var/log/syslog 2>/dev/null
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On Windows run the setup program.
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Documentation
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-------------
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The following documentation is provided:
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* README \-\- this document
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* COPYING \-\- the GNU General Public License
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* INSTALL \-\- generic build & install instructions
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* AUTHORS \-\- authors, credits and additional copyrights
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* userguide.txt \-\- user guide
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* reference.txt \-\- reference document
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* ChangeLog \-\- change log for releases
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Source code documentation will be generated when building from source if
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`doxygen` is available.
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[POP]: https://en.wikipedia.org/wiki/Post_Office_Protocol
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[SMTP]: https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol
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