said by rcnman :

I've forwarded over to the guy who runs email.

You can get port 25 open if you buy a static ip. FWIW.

said by kshakir :

You can hack around the port 25 restriction by using a third party server on another port...

said by NormanS :

OR better yet. You could snmpwalk the modem changing only allow outgoing port 25 to RCN to deny all outgoing port 25 to RCN and allow all others. A 180 it would seem.

Or you could input an invalid IP which you'd never send smtp to thus allowing outgoing port 25 (smtp) to any IP but I thought the first example was funnier.

But like you have to be really really smart and it's really hard and I advise people to never EVER do that! ;p

In actuality, they just don't want people spamming.

=)

jay

said by kshakir :

If you are using a configuration like the one below, you might want to check if people have actually been receiving your emails. Just ran some tests, and I'm pretty sure smtp.rcn.com is silently eating email again. No return-receipts, error messages, etc. I wonder where these messages are going...

Background:
- RCN blocks all outgoing SMTP (port 25) traffic, *except* to smtp.rcn.com. This means you cannot use smtp.yourcompany.com (port 25) to send email from home.
- You can hack around the port 25 restriction by using a third party server on another port, but this is NOT explained in the RCN help.
- Until a few days ago, you could send email from yourname@yourcomany.com using the RCN smtp server, even without login (great for visiting relatives), as long as you wer connecting from an RCN ip address.

What changed, smtp.rcn.com seems to:

- Still relay email if it comes From:
> any_user@rcn.com
> any_user@gmail.com (evidence of a whitelist??)
> (possible other whitelist domains I don't know)

- Silently NOT relaying message From:
> any_user@yourcompany.com
> any_user@yahoo.com
> any_user@( most domains ).com

Net result: If you work at home, you cannot use smtp.rcn.com, nor your own server, to send email for work, and are forced to sign up for a third party alternate-port server like gmail (here's to hoping you don't have certain customer email, which you might not want relayed through google ).

Anyone know how to report this? I spent hours the last time and got nowhere with the CSRs or sales departments. Posted here and it was fixed pretty quickly, so hoping someone is listening again!

(It'd be nice if RCN unblocked outgoing 25, but I understand that we're currently fighting a war on spam.)

said by dehmmy :

Or you could input an invalid IP which you'd never send smtp to thus allowing outgoing port 25 (smtp) to any IP but I thought the first example was funnier.

just put in the Reply-To: line yourname@company.com which will tell the receiving party to reply to that address...

said by NormanS :

Just trying to figure out how that would work.
Not really a satisfactory solution. And a bunch of us, whose ISP gave us Yahoo! mail servers to use, are beating up both our ISP, and Yahoo!, over a similar restriction imposed by Yahoo!.

said by dehmmy :

Yeah, they should at least have deep packet inspection to auto cut would be spammers instead of forcing you to use their smtp.. i agree

said by NormanS :

They aren't forcing you to use their SMTP server. They aren't blocking message submission ports; that I know of. It is just that, when using their SMTP server, they shouldn't care what your "From:" email address is.

said by dehmmy :

Well, in my area at least they block all outgoing port 25 sessions unless it's to one of their smtp servers thus forcing you to use it and no one elses.

said by dehmmy :

Well, in my area at least they block all outgoing port 25 sessions unless it's to one of their smtp servers thus forcing you to use it and no one elses.

jay

said by rcnman :

This is done in order to control outbound spam from zombies on the network. If you want to get around this block you can purchase a static IP that will open port 25.

said by jsolo1 :

Perhaps if all servers required authentication, port 25 could be left open. No credentials, no smtp.