diff --git a/sources/tech/20211109 relaying mail to multiple smarthosts with opensmtpd.md b/sources/tech/20211109 relaying mail to multiple smarthosts with opensmtpd.md new file mode 100644 index 0000000000..f0d165e51a --- /dev/null +++ b/sources/tech/20211109 relaying mail to multiple smarthosts with opensmtpd.md @@ -0,0 +1,85 @@ +[#]: subject: "relaying mail to multiple smarthosts with opensmtpd" +[#]: via: "https://jao.io/blog/2021-11-09-relaying-mail-to-multiple-smarthosts.html" +[#]: author: "jao https://jao.io" +[#]: collector: "lujun9972" +[#]: translator: " " +[#]: reviewer: " " +[#]: publisher: " " +[#]: url: " " + +relaying mail to multiple smarthosts with opensmtpd +====== + +I like to use a local smtp daemon for sending email from my laptop, because that way i can send emails even while disconnected and, even when the network is up, because i don't have to wait for the network protocol to be completed with a remote smarthost. Oh, and i also need local mail delivery. + +For many years i've used postfix to those ends; it has an acceptably simply-ish configuration; but recently i've become fond of VPNs ([mullvad][1], if you want to know), and was annoyed by its getting confused when `/etc/resolv.conf` changes (for instance, because you get the VPN up after postfix's service has started). I've found a pleasantly simple alternative: [OpenSMTPD][2]. + +Say i want to use the SMTP server fencepost.gnu.org when sending an email as [jao@gnu.org][3] and smtp.jao.io when writing with [mail@jao.io][4] or [news@xmobar.org][5] in my `From` header. OpenSMTPD let's you do that with a very simple configuration file in `/etc/smtpd.conf`[1][6]: + +``` + + table aliases file:/etc/aliases + table secrets db:/etc/mail/secrets.db + + table sendergnu { jao@gnu.org } + table senderjao { mail@jao.io, news@xmobar.org } + + listen on localhost + + action "local" mbox alias + action "relaygnu" relay host smtp+tls://gnu@fencepost.gnu.org:587 auth + action "relayjao" relay host smtps://jao@smtp.jao.io:465 auth + + match for local action "local" + match for any from mail-from action "relaygnu" + match for any from mail-from action "relaygan" + +``` + +where we have also configured local delivery for a good measure. That's the full configuration file! The only other thing needed is generating the `secrets.db` file with the users and passwords corresponding to the keys `gnu` and `jao` (those are just arbitrary names). To that end, we create a plain text file with them, using entries of the form ` :`: + +``` + + gnu jao:my fencepost password + jao mail@jao.io:xxxxxxxxxxxxxxxxx + +``` + +where my user for `fencepost.gnu.org` is `jao` and for `smtp.jao.io` is `mail@jao.io` (you see there's no need of escaping spaces or ats). Then we use the program `makemap` to create the secrets db: + +``` + + makemap secrets && rm secrets + +``` + +### Footnotes: + +[1][7] + +That's the default configuration file in my debian box; other popular alternative is `/etc/openstmpd.conf`. + +[Tags][8]: [sundry][9] + +-------------------------------------------------------------------------------- + +via: https://jao.io/blog/2021-11-09-relaying-mail-to-multiple-smarthosts.html + +作者:[jao][a] +选题:[lujun9972][b] +译者:[译者ID](https://github.com/译者ID) +校对:[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译,[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://jao.io +[b]: https://github.com/lujun9972 +[1]: https://en.wikipedia.org/wiki/Mullvad +[2]: https://www.opensmtpd.org/ +[3]: mailto:jao@gnu.org +[4]: mailto:mail@jao.io +[5]: mailto:news@xmobar.org +[6]: tmp.zHAc8OxDnm#fn.1 +[7]: tmp.zHAc8OxDnm#fnr.1 +[8]: https://jao.io/blog/tags.html +[9]: https://jao.io/blog/tag-sundry.html