From my short experience,

we run 2 directors and 3 dovecot servers behind them, with approx. 800 concurent users/dovecot server without any problems. During peak times, they go as high as 2000-2200 users/dovecot server, again without any problems. These 2 directors are behind a haproxy, so i'd say each director handles at approx. 1200-3500 concurent connections without problems.

You may face problems with limitations on your OS if you plan to serve such an amount of users though. It depends on the OS you use.

i hope this helps,

John

On 15/12/2020 13:25, tim@linux-daus.de wrote:

Hi,

currently i'm going to evaluate the Dovecot Director. Are there someone with experience how the Dovecot Director does scale?

The last current information i could find was a post on this mailing list from 2012: 4 Directors are well known, >75 are too much.

Are there any more up to date experience regarding how many user (current and new/s) a single Dovecot Director/proxy node could handle and how many director nodes in a ring are known to work (well)?

Best regards, Tim