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They Blocked My SMTP, Now What?
mindsuck asks: "As of this Wednesday, my ISP blocked my port 25, leaving my mailserver useless to the outside world as a consequence of spammers and their nasty worms. So I decided to ask the nice people of Slashdot. What can I do now to restore my smtp service, besides changing ISPs, is there a obscure way to run a mailserver off a non-standard port? What about services similar to those provided by dyndns.org for this kind of situations? Pros and Cons of using this services? Should I move my MX to a more 'stable' server than my homegrown one?" This topic was last touched upon in this article, from 2002. It's been over a year since SMTP blocks have become commonplace. Have you noticed a slowdown in your SPAM? Are ISP SMTP blocks really helping the problem? Updated: It looks like Charter is also blocking SMTP. Might there be a way to work with your ISP to get them to unblock port 25 for you, if you can sufficiently satisfy them that you are not a spammer?
Krondor wrote in with a similar query: "Charter Communications (in my area) has blocked outbound SMTP connections. I need to be able to send Email to other SMTP servers, besides theirs, for a number of legitamate reasons. My question is this; How can I either still send SMTP to the places I need to, or how can I convince Charter to unblock outbound SMTP (I can understand blocking inbound SMTP without ACK bit set)? They do provide a relay, but won't my messages get labelled as SPAM if I use that? I am also concerned because, this relay is not encrypted with SSL and I don't necessarily trust Charter with that."
First set your smtp server on a different port.
Second find a machine with net access outside of your isp.
Third make an ssh tunnel from that machine to your machine.
That should work perfectly. But nothing is guaranteed.
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I used to use noip.com for DNS stuff. They have a mail reflector service that'll accept mail on their mailserver at port 25 and forward to your mailserver on a non-standard port. It worked okay for me, but the problem arose that cable/dsl residential IPs are listed in many of the spam blacklists. So I ended up with some ISPs I could not send mail to. Ended up upgrading to a small office commercial connection. My servers don't violate the acceptable use policy anymore, I can host anything I want (within reason) and I don't have problems with blacklists.
Keep in mind that if you want to pay commodity prices for a service, you are going to get a service that has been sanitized and developed for the masses. What you're asking is essentially the same as "How can I get WinXP-home to work as a good server?".
If you want to connect to outside SMTP servers, you'll either have to go with a smaller ISP that doesn't have paranoid, 'we're not going to be the front for spam' policies in place (and make a sacrfice, be it limited dialing area, higher prices, or whatever) or tunnel out to a server that will allow you to connect to foreign SMTP servers.
For recieving mail, I understand the need to have a dedicated server, but I have always wondered why it is considered standard and okay to send outgoing mail through a seperate server. It doesnt make sense to me at all- why do e-mail programs not just connect directly to the servers they are trying to send mail to?
(this is just ignorance, I'm actually wondering why)
-- 'The' Lord and Master Bitman On High, Master Of All
Once a month or so, I get a message from the mail server "Delivery unsuccessful: Unknown recipient 'relaytest%security.rr.com'". If they find an open relay, then they'll do something about it; otherwise, I'm free to run my mail server.