When I attempt to send mail, why am I getting error messages saying that the "SMTP server could not be found or is not responding?"

Some Internet providers, (particularly AT&T and MindSpring) have recently started blocking port 25 in an attempt to help prevent unsolicited email from outside sources being sent through their servers. Unfortunately a side-effect of this practice is that it prevents users from accessing our SMTP server. If you are getting error messages when you try sending mail which state that smtp.webcom.com/~webcom is not responding or not found, contact your ISP, and find out if they're blocking port 25. If they are, talk to them about it. They may be willing to remove the block for you. If they are not, you have two options:

Firstly, you can use your ISP's SMTP server to send mail instead of WebCom's. A lot of the time this will solve your problem. Sometimes, however, an ISP will not allow email to be sent through their SMTP server with a different domain. In other words, you may only be able to use their SMTP server if you have your reply address set to your ISP-based email address, not your custom domain name address that you have at WebCom. If this is the case, once again talk to your ISP. They may be able to make exceptions for your addresses or your domains.

Your only other option is to use a different Internet Access Provider that will not block port 25.