Outlook won't send mail

[Charlene]

Outlook won't send mail. I can send mail from any other place on my
computer. Even one small e-mail won't go through. Unless, I connect to
someone else's internet provider and then it will send from outlook. I can't
figure this one out.

 

[K. Orland]

It sounds as though it could be an authentication issue to your mail servers,
but it's hard to tell with such vague details. Please provide your version of
Outlook and the entire send/receive error message(s).

 

[N. Miller]

Outlook won't send mail. I can send mail from any other place on my
computer. Even one small e-mail won't go through. Unless, I connect to
someone else's internet provider and then it will send from outlook. I can't
figure this one out.

Neither can I; and I am pretty good at figuring out email issues. The
critical information is missing.

You can send when connected through somebody else's provider, but not your
own. Whose email service are you using? Doesn't sound like you are using
your own provider's email service. Could it be that your (unnamed) provider
blocks message submission to servers other than their own on port 25? AT&T
does that automatically, and Comcast will do that if a customer has
unusually high volumes of SMTP traffic. In either case, the solution is to
use the proper message submission port for the third party email service;
either port 587 (stated as "preferred" in RFC 5321, and defined for message
submission in RFC 4409), or port 465 with SSL enabled.