Home -> Support Home -> How to: Change the SMTP Port on Networks that Block the Default SMTP Port (125)

How To: Configure Outlook Express™, Outlook™, or Windows Mail™ on networks where port 25 is 'blocked'

Using Microsoft Outlook Express™? Click Here
Using Microsoft Outlook™? Click Here
Using Windows Mail™? Click Here

Many ISPs are blocking what is called "Port 25" which is the port used to send e-mail. They are doing this to cut down on the amount of spam that is sent from their networks.

All e-mail sent via the Internet is routed through the port 25, the channel used for communication between an e-mail client and an e-mail server. Even though port 25 blocking will probably become an industry standard, however, the filter can create problems for e-mail servers and block legitimate e-mail as well as spam.

Port 25 blocking allows ISPs to block spam sent out through their networks, but it tends to punish the innocent that have a need to send through e-mail servers other than those belonging to their ISP. The ISPs that block port 25 require their SMTP server to be used instead of the remote SMTP server or a SMTP server running on your computer.

To Allow Sending of E-mail from these ISP's that Block Port 25, an additional Port (125) has been configured for use with our domains. All E-mail Client software defaults to Port 25. Below are instructions to update the Port Number used to Send E-mail.

Changing SMTP Port on Microsoft Outlook Express™

• Open Microsoft Outlook Express™
   
• From the Tools Menu, choose Accounts
   
• On the Internet Accounts Screen, Click the Mail tab, then Click the E-Mail Account you wish to change. Click the Properties button on the right.
  
   
• On the Advanced Tab of the Properties Window, change Outgoing Server (SMTP) to 125 then click OK
  
  
   
• Click the Apply Button
   
• Click the OK Button
   
• Click the Close Button on the Internet Accounts Window
   

Changing SMTP Port on Microsoft Outlook™

• Open Microsoft Outlook ™
   
• From the Tools Menu, choose Account Settings
   
• On the Account Settings Window, Choose the E-Mail Account You Wish to Configure and Click Change
  
   
• Click the More Settings Button
  
   
• On the AdvancedTab of the Internet E-mail Settings Window, change Outgoing Server (SMTP) to 125 then click OK
  
  
   
• Click the Next Button
   
• Click the Finish Button
   

Changing SMTP Port on Windows Mail™

• Open Windows Mail ™
   
• From the Tools Menu, choose Accounts
   
• On the Internet Accounts Screen, in the Mail section Click the Account you wish to configure then click the Properties button on the right.
  
   
• On the Advanced Tab of the Properties Window, change Outgoing Server (SMTP) to 125 then click OK
  
  
   
• Click the Apply Button
   
• Click the OK Button
   
• Click the Close Button on the Internet Accounts Window