Hi,

I've set up postfix as mail server. and am able to receive mail from both i-net and locally.

But all my outgoing mail is not being delivered! Locally it works, I have not changed any port in postfix config-files.

I then read about my ISP maybe blocking outgoing smtp ports. I'm able to send mail to my ISP- smtp servers(my ISP mail account). It says that port 334 is open instead!

How to check the theory of blocked outgoing smtp ports? Is there a way to bypass the firewall by changing the outgoing ports locally?

Any config files would be posted at request.

Any help would be appreciated.

Hi,

why Port 334? Mail is delivered via Port 25 or 465(SSL).

Where do you deliver mail to? directly to the recipients SMTP server?

Mostly SMTP servers will not accept mail from machines with dynamic ip addresses or from machine having no reverse lookup in DNS.

Could give a clear statement what error messages appears in your maillog?

What I ment to say is that isp has blocked outgoing port 25 and opened say 334 instead!

the mail is sent to anyone on i-net, the only mail is coming to it's destination is one sent to ISPs smtp server. my e-mail account which I got from my ISP.

maillog says "no route to host" when i send to @yahoo.com and "sent ok" when i sent to my e-mail account at my ISPs smtp server.

My question remains, if my ISP has outgoing port 25 blocked(which it has) is there any solution on how to bypass this issue?

using fedora 10 and latest postfix from repo.

Why don't you relay through your ISPs smtp server, just as you would if your were using an email client like thunderbird?

look at Postfix's relayhost parameter in main.cf

Because i don`t see that is a problem of port because as you said you can send locally.
Do you have a dynamic IP or a static IP ? because can be that your emails are bloked by hotmail , yahoo ..... if you have a dynamic IP.

Hi, I did implement this after I started this thread. It does work, but will it aslo work with ssl? I'm plannig on implementing ssl, that all my e-mail is encrypted as it goes out!

thanks.

Hi and thanks for the reply!

by locally i mean local network.

And i mean that my ISP is blocking 25 to the i-net, that has nothing to do with my local network...

I use dynamic dns to resolve dynamic ip issue.

As above answer says it's possible to use relayhost.

but will it work with encryption?

Check with your provider if they support ssl
However, ssl will only be used to encrypt your password, not the mail itself.
If you want to encrypt mail, take a look at PGP