Have you tried to use a different port #. A lot of people will change 25 to 2525 because it is less likely to be blocked.
You can change this in Outlook by going to:
Tools, Options, Mail Setup tab, E-mail Accounts…, (selecting the account), Change… (sometimes marked as Edit…), More Settings…, Advanced tab, Change your Outgoing (SMTP) server as needed, click Next, Finish, then OK.
Good luck. I do not know if your question requires a more technical solution, in which case I would not be of much more help.