Changing Outgoing Port in Outlook
From HostBaby Wiki
Sometimes ISPs (internet Service Providers) will block your outgoing mail port in order to prevent spam being sent on their servers. This can be a pain to innocent emailers such as yourself. Luckily changing the outgoing port will usually resolve the issue.
1. Open Outlook 2007
2. Select the Tools menu and select Account settings
3. Select the account and then select Change

4. Select More settings

5. Select the Advanced tab
6. Change the Outgoing Server (SMTP) port to 465
Under use the following type of encrypted connection select SSL

7. Select OK then Next and then Finish and you're done.