Using Sieve filters with Synology Mail Station

Sep 13, 2019

The Synology Mail Station is a very easy way to self-host your mail if you already own a Synology NAS. I myself use it for my own mail addresses and it works like a charm!

Sadly, I found that one feature was missing: How can one add Sieve filters for their own mail? In case you don't know, Sieve filters are a very useful tool to filter mail on the server side, which is quite convenient if you access your mails on different clients and platforms. Luckily for me, Dovecot (the Mail Delivery Agent used by Synology Mail) has a plugin for Sieve and this is even enabled by default since DSM 4.3.

Therefore, you only have to create a .dovecot.sieve file in your user /home directory and put all your filter rules in there. If you need a tutorial on how to write a Sieve script, I like the one from ProtonMail.

That's it! See you next time :)