outgoing mail problem(s)

[GuppieXX]

Ok, so I just got comcast high-speed cable internet, and it's all well
and fine, except for when I try to use outlook to send mail. I
currently have two mail accounts setup in outlook, my college account
(IMAP/SMTP) and my new comcast one (POP3/SMTP). Originally, my comcast
account was setup in outlook express, but since I use outlook for the
calander and stuff, I wanted to use it through there, so when it asked
if i wanted to import the account settings (when i first started it), I
did, and that's where my problems have begun. I've e-mail comcast
repeatedly, and all everything I've gotten.... doesnt help at all.
Their first response was copied/pasted out of a help file or something
they have.... anyways, I went into express, and got it so that my
accounts work fine in there, with my college one being the default
account, but when I went back into a freshly reinstalled outlook, and
imported the settings, I was unable to send mail from my college
account. Almost as soon as i'd press send/recieve, I'd get a message
in my comcast inbox saying "System Administrator" and "Undeliverable:
<message subject>" and it wouldnt send. I could send fine out of my
comcast account, and recieve in both, but cant send from my college
one. This morning, after I sent them a 2 page explaination, as well as
screen shots, they sent me a message saying that my outgoing mail
server for both accounts should be smtp.comcast.net , so i changed my
college account to those settings, and can now no longer send mail from
either account. If anyone has any idea.... I'm open for suggestions.
Thanks.

 

[Vanguard]

Sounds like you are trying to connect to your college email account on a
different domain (network) than the domain on which you connect at home.
Most non-spamming ISPs will not relay SMTP traffic because that's how
spammers hide or abuse networks. They won't relay SMTP request from
their network to an SMTP server somewhere off their network which allows
the sender to lie about their originating domain. They will not allow
some unknown user from a different domain to access their on-domain SMTP
server because, well, they don't know it's use because your login
authentication was with that other domain, not theirs.

Use the SMTP server for the network on which you connect, not some SMTP
off of their network. If connecting at home then use your home ISP's
SMTP server. Alternatively, you can try to authenticate to the SMTP
server that is on another domain. Configure your e-mail account to
authenticate to the off-domain SMTP server.