alt Hacker NewsYou can argue that you not obligated to use message-id but if you don't use it you should blame only yourself that your messages are not accepted. In requiring message-id I would side with google (though in general I think they anti-spam is too aggressive and lacks ways to report false positives). Full RFC compliance (as in not only MUST but also SHOULD unless you have a very good reason) is the easiest part of making sure your emails will be delivered.
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On the other hand, by erroneously treating a SHOULD as a MUST, I would say that Google is the one who's not RFC-compliant
What is the point of SHOULD then?
(No seriously, I’m asking; are there examples of where it’s actually different from a MUST)?
Also this reminds me of something I read somewhere a long time ago: when specifying requirements don’t bother with SHOULD. Either you want it or you don’t. Because if it’s not a requirement, some people won’t implement it.
I guess the one time it’s good is if you want an optional feature or are moving towards requiring it. In this case Google has decided it’s not an optional feature.
> if you don't use it you should blame only yourself that your messages are not accepted
I think it's a gray area
- If the receiver declines your message because "Message-id" is required - then I blame the receiver; because that's not true
- If the receiver declines your message because "most systems do include it, and it's lack of presence is highly correlated with spam email", then it's on the sender
Admittedly, the end result is the same.