Arif Khokar <arif.i.kho...@gmail.com> writes: > One concern I have regarding this idea is whether or not SMTP servers > typically replace a Message-Id header set by the client.
The clients are supposed to give Message-IDs, but because some clients fail to do so, SMTP server implementations are allowed to add an ID to avoid leaving a message nameless (IIRC, 6.3 in RFC2821). So "replace" would be in violation. But some parts of the world ignore RFCs, so...
