Email – Why Use SMTP Port 587

E-mail Can Be Received But Not Sent

First and foremost, please note that we are NOT your ISP. We simply host your web site and sometimes e-mail. Your ISP would be someone like Verizon, Comcast, Earthlink, etc.

Second, if you can obtain your e-mail through the web mail interface, then the server and e-mail system are working fine.

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.
Port 25 blocking allows ISPs to block spam sent out through their networks, but it tends to punish people using their own domain for e-mail, as e-mail addressed in that manner can no longer be sent through your ISP.

This only affects outgoing e-mail! If you can receive e-mail but not send it, then there is a 99.9% chance this is your issue. If you can send and receive e-mail through web mail, then there is a 100% chance this is your issue. If your technician has told you that the problem is with your web host, but you can use web mail normally, we would suggest outsourcing this issue to a different technician or company.
Please note that almost all ISPs are now blocking port 25, and those that do not will be doing so in the near future. Here is a recent news release from Comcast, one of the largest ISP’s in the country:

Comcast, the nation’s largest broadband Internet service, this week began selectively blocking a network loophole commonly exploited by spammers.
The cable giant, whose broadband Internet service has more than 5.7 million subscribers, said it will block what’s known as “port 25” for accounts suspected of sending mass amounts of unsolicited e-mail. The company will implement blocks based on subscriber accounts with the most outbound activity.

To bypass the port 25 blocking you have these options:

Use a different ISP. You can use a different ISP to connetc to the Internet. Smaller local ISPs usually do not block Port 25.

Try using port 587 as your SMTP server.

Use your ISP’s outgoing mail server. Contact your ISP and ask them for the correct settings for the mail servers.

Unfortunately, we, as your web host, cannot support or correct issues concerning your ISP. If web mail is working, but your e-mail client is not, you will need to contract with a qualified technician or contact your ISP for additional help.

Print Friendly, PDF & Email