On 02/13/2017 11:41 PM, Junio C Hamano wrote:
Arif Khokar <arif.i.khokar@xxxxxxxxx> 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...
Based on my testing, gmail and comcast (and my work email) will preserve
the Message-Id header set by the client, but
hotmail.com/live.com/outlook.com will replace it with their generated value.
Based on a small sample of email addresses of those who post to this
list, it appears that most people are using their own MTA to send email,
or are using gmail, so they probably wouldn't be affected by the issue.