Port 25 blocking
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. This can be the case even if sending was working recently as some ISP's roll these changes through without warning.
Checking if Port 25 is blocked
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, we've included directions below to test port 25 blocking via the command line.
To test if port 25 is blocked, open your command line on your local computer. For windows users, you can access this via start > run > cmd. Mac users can use the "Terminal" application. Once on the command line, type: (Note! Be sure that you replace example.com with your actual domain name)
telnet example.com 25
Port 25 blocking - Fixes
If your ISP does block port 25, you can work around it in either of three ways:
The Preferred Solution
As your ISP is blocking port 25, the preferred solution is to use the outgoing mail server provided by your ISP. As each Internet Service Provider has different settings you will need to use (such as username and password, smtp server...), you will need to contact your ISP for the correct settings. We do have alternate solutions to this which involve going over port 465 or 587 instead of 25, however if your ISP begins to block 465 or 587 in the future, you will once again be unable to send email.
Alternative Solution #1
Beginning in late March 2010, we are updating many of our servers to run SMTP over port 587 as well as port 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.
Alternative Solution #2
Use the secure, or SSL, port for outgoing mail. This will involve selecting the setting "this server requires a secure connection (SSL)" in your mail program. You only need to make this change for the outgoing mail server. Once you check that box, then change the port listing from 25 to 465 and save the changes. These settings are usually found in the advanced settings of your email client. Please see the end of this article for more details.
You will also want to change the outgoing server name to secure##.inmotionhosting.com, secure## being the secure alternative of the actual server you are on. For example, if your Welcome Email states that your account is on biz54.inmotionhosting.com, your outgoing server name should be secure54.inmotionhosting.com.
If you are unsure, please tech support. This option will work in most cases, however we cannot guarantee that your internet service provider will not some day in the future begin to block port 465. Below are instructions to change the ports for the most common Email Clients.
