First of all you need to make sure the mail server supports SSL for SMTP. And if it does, you also need to know on which port. The default port in Outlook for SMTP is 25, but in Google for example SSL is supported on port 465. Also your mail server might support other security protocols for SMTP, like TLS. Again Google establishes TLS connection on port 587. So really, you need to go your mail provider support and obtain this information from them. You can't really guess what combination of protocols and ports they are using.
All these settings in Outlook can be changed at: File -> Info -> Account Settings -> Email tab -> Select email account -> Change -> More Settings -> Advanced tab