Unable to Send Email when away from Home or Office (Port 25 Blocked)

If you cannot send email while you're away from home, and you're a guest on another network, that ISP may be blocking SMTP Port 25. Port 25 is the standard port for sending email. It is also used for sending spam which results in many ISPs blocking its use to thwart spammers.

In order to send email again, you'll have to change to a different SMTP port. Please use Port 587.

For instructions on changing the SMTP Port for sending email, please see the following Knowledgebase article:

SMTP Port Blocking

  • Email, Troubleshooting, Standard Email, Ports, SMTP
  • 0 Users Found This Useful
Was this answer helpful?

Related Articles

Cannot Send Email

I am having a problem sending email. I can receive email, I just can't send. Are you using an...

SMTP Port Blocking - How to Change the SMTP Port

Some ISP's block SMTP relaying as a security precaution to thwart spammers. This means that you...

Email Headers

What are Email Headers? Email headers contain information that can be useful when analyzing...

Barracuda Network Blocked My Email

The Barracuda Spam Firewall is a popular spam filtering solution. Barracuda uses several...

Messages Stuck in Outlook Outbox - will not send

When attempting to send mail from Outlook, the messages will not send and remain in the Outbox....