Dear all, I have recently migrated from my old Debian 8 (jessie) system to a new VM with fresh Debian 10 (buster) installation. Previous dovecot version was 2.2.13 and now I have 2.3.4.1. Dovecot was setup from Debian packages. Mostly, it is working, but one problem is just frustrating me. The number of some pop3-login processes are getting higher and higher until they reach my login_max_processes_count option which is equal 1000. From ps aux it looks like this: dovecot  55067  0.0  0.0   8192  6340 ?        S    00:09   0:00 dovecot/pop3-login [1 pre-login] dovecot  55344  0.0  0.0   8192  6388 ?        S    00:35   0:00 dovecot/pop3-login [1 pre-login] dovecot  55351  0.0  0.0   8192  6268 ?        S    00:35   0:00 dovecot/pop3-login [1 pre-login] dovecot  55354  0.0  0.0   8192  6388 ?        S    00:35   0:00 dovecot/pop3-login [1 pre-login] dovecot  55594  0.0  0.0   8192  6280 ?        S    00:36   0:00 dovecot/pop3-login [1 pre-login] dovecot  56822  0.0  0.0   8192  6300 ?        S    00:36   0:00 dovecot/pop3-login [1 pre-login] dovecot  56996  0.0  0.0   8192  6268 ?        S    00:36   0:00 dovecot/pop3-login [1 pre-login] … Once it reaches the login_max_processes_count value my users start to complain to no new mail is arriving. Restart resolves the problem just for some time, until it will come to a limit next time (sometimes it take 1 day, sometimes 1 hour). In my old system I had nothing like that, but I guess it could be done something wrong during migration. I don’t know if it is significant but instead of real users I deal with only one third-party application which utilizeses 5 simultaneous tcp connections to check mailboxes via SSL\TLS. My dovecot is not public, and there is nothing else besides these 5 connections. Currently, in a config I have this: service pop3-login { process_min_avail = 4 process_limit = 4 client_limit = 100 service_count = 100 Please friends give me a way how to handle the situation. Might it be a bug?

Regards, Greg Semenov