If you are unable to send email, you should first verify that you have your email client configured properly. Please refer to our E-Mail Client Configuration page to ensure your E-Mail client is setup correctly.
Port 25 blocked
If you cannot send mail, the problem is likely a restriction by your ISP (Internet Service Provider) as many block the normal sendmail port 25, due to their own security concerns.
For the average user, the easiest way to find out if port 25 is being blocked is to contact your ISP and ask them. For the advanced user, please use the instructions below to test port 25 blocking via the command line. For windows users, you can access this via start > run > cmd. Mac users can use the "Terminal" application.
telnet your-domain.com 25
If your ISP is blocking port 25, simply change your SMTP port number to 587. This setting is usually found in the advanced settings of your email client. Please see the end of this article for more details. Please note that if your ISP begins to block 465 or 587 in the future, you will be unable to send email.
Alternatively, you may use the outgoing mail server provided by your ISP. As each Internet Service Provider has different settings you will need to use the correct settings (username and password, smtp server and port number), provided by your ISP.