exim question

> The classic sendmail Received: header is easily parsed.  Perhaps
> it would be better if there were a standardized header carrying the
> HELO string, SMTP client IP address, and client host name, along
> with rules about when an SMTP relay should replace an existing
> header, but there aren't.

Actually, that's all laid out in detail in section 4.4 of RFC 5321 and its 
predecessors.  Unfortunately, nobody seems to have read it.  The form of 
an IPv6 literal was in 2821, published in 2001, so it shouldn't come as a 
surprise.

I agree that given the random variation in formats, it would be a good 
idea to make the parser as forgiving as it practically can be.

R's,
John