Hello, (Sorry if this is posted in the wrong area, or already being covered elsewhere, but i am new to ubuntu server, and this issue is driving me mad)

I thank you for any light you may be able to shed on this issue.

I am having trouble with my mail server, i can send and receive mail locally with telnet or netcat via port 25 e.g telnet localhost, i can even telnet mail.example on port 25.

But i can't mail out to hotmail, my mail.log says connection timed out.

Now here is the confusing part, it times out on every port i try...

I have phoned my ISP and they assure me, port 25 is not blocked, it is open on my router and the firewall is not blocking it.

I use postfix and courier (pop and imap)
Is there something else i need?

I am happy to provide additional info, i know it must be something soooo simple i am missing.....

Again, i thank you for any help you can provide.