This morning my outgoing mail abruptly refused to go out. Any of it. My housemate’s mail, too.
Now, given that I have at least 8 separate e-mail accounts (I own four domains and co-own a fifth, as well as having e-mail through the Ur-Guru’s servers and, of course, an account provided by my ISP), that seemed like a problem that had to originate with Comcast. And this time it wasn’t a general outage: I could get incoming mail and access the Web and FTP servers just fine. But no outgoing mail.
Comcast’s online help technician explained that they were blocking Port 25. If you go into the settings for your e-mail program, you’ll find a setting for the incoming (POP) and outgoing (SMTP) servers. And that setting includes a port number. Outgoing mail normally uses port 25.
Except when it’s blocked, of course. Then outgoing mail doesn’t go anywhere.
After the Comcast tech had given me the alternative SMTP port number for Comcast (587), I then had to research the appropriate ports for GoDaddy (3535) and DreamHost (587). But the Ur-Guru doesn’t have any alternative SMTP ports, so we had to switch to SSL, which uses port 465. And even then he had to create a security certificate.
This was a serious nuisance for me, and I’m a fairly geeky sort. To my housemate, all this talk of ports and servers is gibberish. And it doesn’t take a geek to have a domain, a website, and a mail server provided by someone other than the ISP that provides the lines into the home or office.
This kind of blocking must be the reason I couldn’t send mail while I was in Chicago. My father has cable internet from RCN, long known for evil practices of that nature. I bet if I tried again with the alternative ports, it would work.
Blocking Port 25 is allegedly meant to guard against viruses and spam. But I’m sure I haven’t sent anything that could be regarded as spam, and nothing on my machine is infected, either. What’s more, anything that takes over a machine will probably use the accounts as configured to send out the mail, so I’m not at all sure why port 587 would be an advantage over port 25. It seems to me like the kind of decision that leads to a lot of user frustration and a lot of tech-support calls.
And, of course, if instead of finding those alternative port numbers for my other accounts, I had set my outgoing mail server to smtp.comcast.net on port 587, many recipients would reject it because of authentication problems, since a return address that doesn’t match the mail server’s domain is one of the indications that a message is spam.
Something to watch out for when you sign up with a new web host: do they provide an alternative to port 25? Because it’s not often we can avoid signing on with companies like Comcast that choose to block our basic communications.