On 6/14/2014 6:16 AM, Joseph Brennan wrote: > > Vincent Fox <vbfox@xxxxxxxxxxx> wrote: > >> I have recently noticed that certain malformed messages hang POP3 clients. >> The pattern is that the mesages all have obscenely long last lines. I >> can see it >> when I set up debug log dir for the account, that the download of the >> message >> proceeds fine up until 2048th character and then stops. > > How is that possible? The SMTP maximum is 1000 including the CR LF pair. > I'm surprised a message like that is accepted by your MTA and/or LMTP. If > Cyrus IMAP handles up to 2047 characters that's very generous. > > As I researched further after this message I realized that it shouldn't. When I look through my sendmail configuration at the various mailers I note the SMTP have L=990, except relay which is L=2040. BUT the LMTP mailer seems to have no L= at all! So malformed message arrives directly at my MX server from spammer and then is happily delivered by LMTP which doesn't seem to care about long lines or do anything about it. I suppose this wouldn't occur if I were using SMTP to my backends but I thought it was preferred. Yes I am realizing now this is not a Cyrus/POP problem per se, and I need some layer on my mail router to take action on the message body issue. Thanks! ---- Cyrus Home Page: http://www.cyrusimap.org/ List Archives/Info: http://lists.andrew.cmu.edu/pipermail/info-cyrus/ To Unsubscribe: https://lists.andrew.cmu.edu/mailman/listinfo/info-cyrus
