Hello. Thanks to all for your suggestions. I'm going to replace procmail now. On that one mailbox it was not even really used (procmailrc was empty).
On 8/9/19 7:34 PM, Gilles Chehade wrote:
it was not necessary with OpenBSD 6.3 because OpenSMTPD was doing things wrong by prepending it itself in some cases and not in others. with OpenBSD 6.4, the mda layer was normalized so that there are not any special cases anymore, which means the procmail command line option must be used now.
This explains the changed behavior. Good to know. Bye, Michael