Having written multiple RFCs, violating the RFC is not always a bad thing. Some of the MUSTs are a result of the committee process, and follow the lowest common denominator.
If the recommendations don't make sense, don't follow them.
If the recommendations don't make sense, don't follow them.
In general, I would tend to agree -- so long as you aren't "hurting" (affecting) anyone else.
OTOH:
$ tail -n 4 ~/.signature
"The total budget at all receivers for solving senders' problems is
$0. If you want them to accept your mail and manage it the way you
want, send it the way the spec says to." --John Levine
I'm responsible for a bunch of mail servers and occasionally get reports that messages from some random sender to a mailbox on one of these servers is not being accepted. More often than not, it's because RFCs aren't being followed (WRT SMTP, I'm not very liberal in what I accept). Of course, they will demand that I "fix" my "broken" servers that are refusing to accept their messages. Sometimes the non-compliance is intentional but usually it is simply out of ignorance (especially true when the remote host runs Microsoft Exchange); I try to point them at the RFCs, explain why their mail is being refused, and what they can change so that the mail will be accepted.