> I apologize for bringing perhaps trivial/well-known matter, but I am > interested in your opinion. > > RFC 5322 clearly states that mail messages SHOULD contain a Message ID > identifier, but if the do contain it, it MUST be globally unique. > > Despite this requirement, I have encountered senders (namely Spamcop) > that sends obviously different (albeit related) messages called "Alert" > and "Summary" (they are always related to the same incident and have the > same Message ID). This creates all sorts of problems when processing > these mails, namely with users that have local forwards from one domain > to another (our mailserver hosts multiple domains), because for example > Dovecot refuses to forward the second message, flagging it as a duplicate. > > My question to you is - did you also encounter similar incorrect > (according to RFC standards) problem, and if so, is there a way to > persuade dovecot to perhaps determine the uniqueness of a message by > other means than just checking the message ID (i.e. look at other > identifiers, Subject, perhaps)? Because according to the log records, > Spamcop does not seem to be the only offender. >
I would think this is more related to MTA's then dovecot. It is dovecot's core job to put messages in mailboxes. However interesting this globally unique. At first sight, I would say a bit unnecessarily broad. I would recommend using a mail filter in any mta, grab whatever you want and analyze that, with that solution you can add any header you like. I do not get what spamcop has to do with this, afaik this is a dnsbl.
