How to amend your SMTP port in Microsoft Windows 8 Mail
Some Internet Service Providers (ISPs) will routinely block sending mail on the default port 25. To remedy this, follow the simple steps listed below. These will take you through the way to change your port to 587 which will allow mail to be sent.
Step 1. Open the Mail app and use your finger to swipe from the right-hand bezel of the display towards the centre. This will bring up the Charms bar. Now tap Settings at the bottom.
Step 2. Tap Accounts which is underneath Settings
Step 3. Now select the account you want to amend the port for. This is underneath Settings
Step 4. Scroll down the pane until you see the Server Settings. Now update the outgoing server port to 587.
Step 5. Select and click the Back button in the settings tab to save the changes