I suggest people should include their domain name in a post, especially with mail-related problems. If someone is having trouble receiving mail, the first thing I'm going to want to do is test and see if it's one of the usual forehead-smackers
My tests are usually something like:
Code:
$ dig +trace example.com mx
(check for sensible delegation/NS records, see if the MX record is there)
$ dig example.com mx
$ dig example.com soa
(see what I've got cached)
$ dig +trace example.com
$ dig example.com
(check the A record for example.com)
$ dig mail.example.com (or whatever the MX says)
$ dig www.example.com
(do they imply they just have one linode? if so, make sure the IPs "match")
$ whois 192.0.2.1
(is it a linode IP?)
Then it's time to start sweet-talking the SMTP server...
Code:
$ nc mail.example.com 25
<<< 220 framboise.example.com ESMTP Postfix cause I speak of the pompatus of love
>>> HELO blah
<<< 250 framboise.example.com
>>> MAIL from: <rtucker@hoopycat.com>
<<< 250 2.1.0 Ok
>>> RCPT to: <asdfasdf@example.com>
<<< 504 5.5.2 <blah>: Helo command rejected: need fully-qualified hostname
>>> URMOM
<<< 502 5.5.2 Error: command not recognized
... you get the idea.
Sure, I can ask "so, what does it look like when you do 'dig +trace domain.com mx'?", but... well, that takes a loooong time. Especially when it turns out their local ISP blocks port 25 outbound and that's the whole problem...
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Code:
/* TODO: need to add signature to posts */