[snip]
Ok, this user is using my courier as a relay (authenticated smtp), however
64.80.255.252 is NOT my server's IP. My server's IP (the relay being used)
This was merely a guess. I saw the IP in the email and assumed it was some
sort of tracking.
is 38.118.152.246. I'm guessing that perhaps that is the IP of his email
client? But if so, it doesn't make sense because shouldn't the IP be the
one
of the email server that is relaying the message?
Yes, SPF will check against the IP of the mail server.
[snip]
My main domain is indeed americasnet.com... however that is not the domain
that the user is providing when utilizing the relay. Which domain would I
need to add to spf.pobox.com ?
The user's domain is the one that need's an SPF record. Basically, SPF
records say this:
- Any legitimate mail that comes from me will only come from the following
IP addresses
So, if your friend has say, a gmail.com address and tries to send through
your server, he'll be rejected if the recipient server has a strict SPF
filter.
gmail.com. 78 IN TXT "v=spf1 a:mproxy.gmail.com
a:rproxy.gmail.com a:wproxy.gmail.com a:zproxy.gmail.com a:nproxy.gmail.com
?all"
gmail.com says that real gmail email comes from the above servers, none of
which are 38.112.152.246 etc.
[snip]
I guess a better question is, what exactly is the error? Is it the
destination server (joimail.com) rejecting the message because of some
misconfiguration on my server?
The answer is exactly as I described before. The destination server
(joimail.com) is rejecting the message because the sender of the mail is
failing SPF checks. What's the domain of the user in question? Perhaps
it'll be easier to show you once you give that information.
Michael