Alternative to opening port 25 to the world

[krisleech]

Wonder if anyone can help. I have recently changed ISP. My old ISP was delivering email to my static IP by SMTP. This email was being picked up by our mail server and distributed via IMAP to our email clients.

So the firewall allowed traffic through port 25 from the ISP's IP only. No problem as i am not opening up port 25 to the world and am still stealthed.

However the new ISP does not have the facility to forward email to us, instead they ask us to open port 25 to everyone. I guess this is because they simply set up the DNS to forward mail directly to us, so mail could come from any IP. Where as before the DNS was pointing to the ISP's mail server which collected the mail and forwarded it to our static IP. I may have got this wrong but thats the way it appears.

I dont really want to open port 25 to the world so what to do?

Change ISP again (i have a years contact) or transfer my domain to another service who can collect mail and forward it to me? Can anyone suggest a service to do this? Or some other method?

By the way the domain is used only for email no web.

Thanks for any help, K.

[Kevin]

The service you are talking about is usually called an "SMTP relay". It is not a common ISP feature even in the commercial ISPs but some do it. I have seen companies on the internet that provide that service but I can't remember any off the top of my head. It doesn't have to be provided by your ISP.

As far as opening up tcp/25 to the world that would all depend on what is running on that port and how it is configured. Some email server software is more secure than others and some need to be configured to be secure. My port 25 is open to the world but I have qmail-smtpd listening on it which is a program that I trust.

[krisleech]

Thanks Kevin that has really helped, at least i know what im looking for, either an SMTP relay service or a secure mail server.

Is there a relay service you could recommend?

Cheers K.

[Kevin]

Thanks Kevin that has really helped, at least i know what im looking for, either an SMTP relay service or a secure mail server.

Is there a relay service you could recommend?

Cheers K.
The only company that I know that does it is EasyDNS. It is part of their DNS+ package which is $39.95/year. However I have never used that service from them and I don't know anyone who has.

For secure email server I would of course recommend qmail. That is what FutureQuest uses and that is what I personally use. Postfix also seems to be a popular choice in the UNIX world but I haven't tried it myself. I would not recommend using sendmail due to its history of security problems (and extremely ugly configuration).