I doubt they are trying to cut off competition to GMail. Email is blocked typically as a matter of convention by the majority of ISPs. It requires features 99.9% of customers don't care about in the slightest, and invites spam problems.
It may be blocked by the ISPs that service a majority of people (i.e. cable companies), but I don't have any reason to think that it's blocked by a majority of ISPs.
I actually butted heads with this part of the AUP when I was a teenager.
I was young, naive, and trying to set up my own mail server.
Ended up creating an open SMTP relay instead.
Received a phone call within 15 minutes of successfully testing my mail server! They were calling to tell me they suspect a computer in my house has a virus. I chatted with support for a while and we eventually figured out it was my mail server.
They were rather pleasant about it actually, they explained that it doesn't necessarily violate their AUP but it's hard to configure a mail server correctly.
I'd later learn that since my IP address was from their dynamically allocated pool: most popular mail servers would reject my messages as spam anyways.
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This was with TimeWarner cable about 7 or 8 years ago.
Most likely. But it's trivial to see whether or not someone is running an SMTP server whereas it's more difficult to determine if they're running an open relay.
Wouldn't it be a simple matter of just trying to send an email using the server in question? If you receive the email you just sent, then it's an open relay.
So now you have to have an email account somewhere that allows anything and everything to be sent to it (no spam filtering), and you need a system to send emails and correlate that with received emails. This is all certainly possible and not necessarily that difficult, but compared to seeing if a service is running on port 25 it's about a hojillion times more hassle.
You don't need to send. Send "helo", "mail from" and "rcpt to" commands and most servers that are not open relays will reject the message after the rcpt to. Issue a "data", and most remaining ones will. At which point you can disconnect without sending any e-mails. Open relay testers are dime a dozen.
Mine doesn't (Roadrunner). I run my own SMTP server off my cable modem. I have no problems getting incoming mail. Outgoing, however, was a pain because so many SMTP servers block mail coming from dynamic IPs. It annoys me to no end. I understand the reasons for doing it, but it annoys me to no end. I had to set up a small satellite server on a static IP that I route all my outgoing mail through.
To search your home, a warrant is needed. To search a remote site, less is needed, and you might never know it’s been searched, back-doored and compromised.
Mostly because the small satellite server requires very little storage, cpu, or memory. I have about 100G of mail on my IMAP server (not all in one account: I run email for everyone in my family), and that kind of space isn't cheap in the server rental business (despite the fact that a 2TB drive is $90).
Plus I just like having my data here, and not somewhere where I have no physical access.
> You'd think outbound would be where all the spam problems come from, though.
They block port 25 to prevent open relays on their network (i.e. someone sends a forged email, the SMTP server does no authentication, and just forwards it on to the destination).
