Hi,
Are the other POP3 servers advertising PIPELINING capability? Maybe try if this happen with it removed from Dovecot? (src/pop3/capability.h, rebuild).
Nope. That wasnt it.
thanks for testing it, I didn't had the time to do it yet. Since we couldn't live with this error, we switched back to qmail-pop3d for the pop3 service, letting dovecot handle imap only. To check if the error disappeared in current releases, I downloaded the latest stable release 20050624. I compiled and installed it, but the error still remained. Downloading of about 1649 messages stopped after the 843rd message, again with the message "-ERR Message is deleted" (src/pop3/commands.c, line 50).
It is really important for us, that this bug is resolved. This shall not sound like a threat, but we are indead evaluating a migration to Courier IMAP (although I never liked it very much), but a stable pop3 service is essential for us. And we don't want to use qmail-pop3d, because it doesn't log anything.
Regards Marten