Port 25 Blocked for SMTP/Outgoing

If you try to send out mail through our mail server (mail.your-domain-here.net or mail.hosting-advantage.com) and find that you are not able to, it could be that your ISP is blocking this mail from being sent by blocking 'Port 25.'  If you are having this problem, please see instructions to fix, or read below for more detailed background information.

Why are they blocking Port 25?

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.

Some ISPs that block Port 25

AT&T MindSpring

BellSouth MSN



Charter  People PC

Comcast ATTBI

Cox Sympatico.ca

 EarthLink Verio





Instructions to fix

You should change your email software to use Port 26 instead of 25.  

Note: Remember if you haven't checked mail in the past 15 minutes and try to send through our server, it won't send.  Simply check your mail then try and send again.

Outlook Express:

Go to TOOLS > ACCOUNTS > Click on Mail Account then click on PROPERTIES.  Go to the ADVANCED tab and change 25 to 26.

Outlook 2002:

Go to TOOLS > EMAIL ACCOUNTS > VIEW OR CHANGE > Select your Account then CHANGE > MORE SETTINGS > ADVANCED > Change outoing port to 26.

Netscape 7

Netscape 6 or lower

Go to EDIT > MENU > PREFERENCES > Click on the Mail Server on Left then EDIT > change your Outgoing Mail server to:   mail.your-domain-here.net:26

In Eudora 5.1 or older:

1. Shut down Eudora.
2. Look in the Eudora directory (probably c:\program files\qualcomm\eudora)
3. In the directory "extrastuff" you will find a file called "esoteric.epi". Drag it to the main Eudora folder.
4. Start up Eudora
5. Go to Tools -> Options -> Ports
6. Type port 26 in the box for SMTP port.

Other Versions of Eudora see this link.