Download your favorite Linux distribution at LQ ISO.
Go Back > Forums > Linux Forums > Linux - Software
User Name
Linux - Software This forum is for Software issues.
Having a problem installing a new program? Want to know which application is best for the job? Post your question in this forum.


  Search this Thread
Old 07-13-2004, 11:26 AM   #1
LQ Newbie
Registered: Apr 2004
Distribution: Mandrake
Posts: 1

Rep: Reputation: 0
POSTFIX: Changed SMTP port - now can't send mail (long)

Hey all,

Here's some necessary info about my setup before I state the problem:

Verizon DSL

Running 3 computers behind a Linksys router/firewall:

One WinXP box (used by my wife and I as our main computer)

One Mandrake 9 box running postfix/imap for mail for my domain.

One Win2003 server hosting Web/FTP for HTTP for my domain.

I have the respective ports for the above services forwarded to the appropriate servers behind the firewall and everything is working great and has been for the last year. I implemented SASL auth for my SMTP server to secure it which also works great. I can send/receive mail through the Mandrake server from inside or oustside my LAN so its all configured correctly. I don't have a static IP but I am using DynDNS which has solved that probelm.

I've been getting some bounce messages from the Verizon account (which is the one we use for our family email) on the XP box which makes me beleive there may be a trojan of some sort on the XP box using my box as a SPAM server. Verizon does not block any ports in my area so this is certainly possible.

I'd like to configure my firewall to block port 25 from LAN to WAN and then use the Mandrake box to handle outbound mail for both my domain and our family Verizon email account.

What I Did:
- Edited and added port 2525 as an SMTP listen port and ran postfix reload.

- Configured my mail clients to use port 2525 for outbound mail and the mandrake box as the SMTP server.

- Closed port 25 outbound on the firewall.

Problem (finally):

The mandrake box accepts mail on port 2525 from my mail clients but never delivers it to any address outside the firewall. I can send mail between computers on the LAN but if I send to anything outside (say a hotmail address) it never gets there.

Can anyone tell me why this might be? Any suggestions?

Thanks!!! (sorry for the length but I wanted you guys to have all the background info).
Old 07-13-2004, 01:40 PM   #2
Senior Member
Registered: Jun 2004
Posts: 2,553

Rep: Reputation: 53
your DynDNS service might have an alternative port to 25 service setup


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Postfix send mail problem(In RH9, kernal 2.4.20, postfix 2.1.5) minor Linux - General 6 09-23-2019 10:09 PM
501 invalid domain name -- when trying to send mail (SMTP) FUXC Linux - General 8 05-01-2012 06:04 PM
smtp problems, can't send mail to other accounts servnov Linux - General 3 09-26-2004 08:17 PM
Using Postfix the send email via another smtp server - to anyone. scarstens Linux - Newbie 1 01-27-2004 03:31 PM
Postfix newbie - send to ISP SMTP server not working deanquanne Linux - Software 2 11-05-2003 01:22 PM > Forums > Linux Forums > Linux - Software

All times are GMT -5. The time now is 06:23 AM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration