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Title: Configure OpenSMTPD to relay on a network |
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Author: Solène |
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Date: 29 October 2018 |
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Tags: openbsd highlight opensmtpd |
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Description: |
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With the new OpenSMTPD syntax change which landed with OpenBSD 6.4 |
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release, changes are needed for making opensmtpd to act as a lan relay |
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to a smtp server. This case wasn't covered in my previous article |
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about opensmtpd, I was only writing about relaying from the local |
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machine, not for a network. Mike (a reader of the blog) shared that it |
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would be nice to have an article about it. Here it is! :) |
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A simple configuration would look like the following: |
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listen on em0 |
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listen on lo0 |
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table secrets db:/etc/mail/secrets.db |
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action "relay" relay host smtps://[email protected] auth |
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<secrets> |
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match from local for any action "relay" |
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match from src 192.168.1.0/24 for action relay |
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The daemon will listen on em0 interface, and mail delivered from the |
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network will be relayed to remote-smtpd.tld. |
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For a relay using authentication, the login and passwords must be |
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defined in the file **/etc/mail/secrets** like this: `myrelay |
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login:Pa$$W0rd` |
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[smtpd.conf(5)](http://man.openbsd.org/smtpd.conf) explains creation |
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of **/etc/mail/secrets** like this: |
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touch /etc/mail/secrets |
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chmod 640 /etc/mail/secrets |
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chown root:_smtpd /etc/mail/secrets |
