For change mail sending port 25 to 587 and receiving port 110 to 995 on Outlook 2010:
1. Click the File tab, then click the Account Settings button.
2. Highlight the specific e-mail account (if there is multiple account) you want to change, then click Change to open the settings window.
3. Make sure the "Incoming mail server" and "Outgoing mail server (SMTP)" is set to: mail.yourdomainname.com or your server IP address.
5. Please check the box for My outgoing server (SMTP) requires authentication and ensure that Use same settings as my incoming mail server is selected.
6. Enter port 995 as the Incoming server (POP3) port and ensure that SSL check box is chosen on the "This server requires an encrypted connection (SSL)" from the Advanced tab.
8. Now please accept the certificate option and ckick on Yes.