On 21 Feb 2019, at 12.23, Hajo Locke via dovecot <dovecot@dovecot.org> wrote: I think mbox+procmail is a classic setup and wide used and good solution for many usecases. Same setup we use many years. We run ~2 mio mailboxes. our automated systems depends on this setup. creating mailboxes, managing mailboxes, creating automated filterrules, backupsystem to tell something of them. we can not switch our whole mailsetup to work around this bug. How to get a dump if dovecot not crashing but has wrong behaviour? I would like to help and provide useful info, but it depends on kind of problem. I think if a classic setup is not working in dovecot any more, this is a serious problem.
In you first email to this thread it says:
Feb 8 08:45:37 hostname dovecot[14882]: imap(myuser): Fatal: master: service(imap): child 14135 killed with signal 6 (core dumped)
So imap is crashing and even dumping a core.
Also I must disagree with your mbox+procmail statement. mbox has always been very unoptimised mailbox format and everyone should be emphasised not to use it. Also that combination has always had problems with indexing and file locking. I would not use it on high volume mailservers. Or even medium volume mailservers.
Sami