1. bluehost knowledge base

Email Troubleshooting - How To Change SMTP Port From 25 To 26

Many ISPs are now blocking port 25. If you are unable to send email but are able to receive, you may need to change your outgoing SMTP server port to 26.

Here are the related instructions for the most popular email clients:

Thunderbird

To change the outgoing mail port from 25 to 26:
  1. Launch the Thunderbird mail client.
  2. Drop down the Edit menu, and choose Account Settings.
  3. Click Outgoing Server (SMTP).
  4. On the right hand side select the server to modify and click Edit.
  5. Change the port number from 25 to 26.
  6. Click OK.
  7. Restart Thunderbird.

Microsoft Outlook and Outlook Express

To change the outgoing mail port from 25 to 26:
  1. In Outlook, drop down the Tools menu.
  2. Choose Accounts or Email Accounts.
  3. View or change existing e-mail accounts should be marked.
  4. Click Next.
  5. Select the account and click Change.
  6. Select More Settings.
  7. In Outlook Express, drop down the Tools menu.
  8. Choose Accounts.
  9. Select the account and click Properties.
  10. Click on the Advanced tab.
  11. Change the outgoing mail from port 25 to port 26.
  12. Make sure that the box for This connections requires a secure connection(SSL) is NOT checked.
  13. Click OK.
  14. Restart Outlook.

Apple Mail 10.5+

To change the outgoing mail port from 25 to 26:
  1. Launch Apple Mail.
  2. Drop down the mail menu, and choose preferences.
  3. Select the email account to modify under accounts.
  4. After selecting the email account, click on Server Settings.
  5. Beneath Outgoing server (SMTP), click on the drop-down bar and select Edit SMTP server list...
  6. Click on your desired Outgoing server and then click advanced.
  7. Select option for custom port and type in 26.
  8. Make sure "Automatically Manage Connection Settings" checkboxes are unchecked so that it allows you to edit the port number.
  9. Click Save.
  10. Restart Apple Mail.