Redirecting to multiple SMTP servers

[garethsh]

I have a situation where port 25 is blocked by my ISP.

I wish to point my MX record to another location where port 25 is allowed by the ISP but this site already has SMTP proxy setup.

Can I setup Wingate so incoming mail for domain xxxx.com.au will be passsed through to the internal mail server (MDaemon) as currently happens, and incoming mail for yyyy.com.au is redirected back out to my mail server on a port that is not blocked.

If this is not possible I will have to write a small server program to accept the SMTP connection from Wingate, examine the RCPT command before deciding to forward the packets to the internal mail server or redirect back out to my mail server.

[adrien]

WinGate can do all of that except maybe the "different port" thing....

WinGate will receive the mail, and forward incoming mail (mail that matches a local domain) to an internal server.

You can also set up a domain that WinGate will relay for.

WinGate will then try and deliver that mail to the SMTP server responsible for that domain.

Can you pull the mail down with POP3?

So your ISP blocked port 25 inbound? Or outbound? Or both? any choice of ISPs where you are?

[garethsh]

I want to use the ISP I'm on for various reasons.

My mail is not hosted elsewhere, I want to host my own domain so POP3 is not an option.

I can send mail out on port 25 no problems. The ISP allows port 25 coming in but does not allow the reply back !!! (Until you realise this you wonder what is going on as you receive the connection from the client but then it times out).

When you talk about setting up Wingate to relay a domain how do you do this? We know about the 'allow relaying' in the SMTP proxy settings but this appears to be open to all, not 'allow relaying for domain xxxx'.

Are you talking about using the Wingate mail server? We use MDaemon as the mail server running on the same PC as Wingate (usually). We setup Wingate SMTP proxy to forwarding incoming connections to 127.0.0.1 port xxxx (to match MDaemon).

[adrien]

OK, it is very odd that they would block your SYN-ACK back to the SYN on port 25 inbound... are you sure this is intentional on their part? You might find they don't mean to do this and just have an incorrectly configured router or something.

As for running MDaemon on the same machine, why do you then need to run it through a SMTP mapping on the same machine? You could just have MDaemon accept the connection from the Internet itself.

You may find that unless the bindings are set up properly, you actually just have a port conflict between your SMTP mapping and MDaemon, and this is what is causing inbound connections to time out.

Is the mapping on port 25 as well as MDaemon running on port 25?

Adrien