[CentOS] Selective Sendmail Relaying.

Wed Dec 20 20:07:08 UTC 2006
Kevan Benson <kbenson at a-1networks.com>

On Wednesday 20 December 2006 08:30, Aleksandar Milivojevic wrote:
> > I know, unfortunately I have a couple of thousand non-technical users
> > already setup and I can't disrupt those.
> Hm, if same system is their IMAP/POP3 server too, you could configure  
> Sendmail to use same password source.  It should not prompt them for  
> passwords when sending mails (since it's the same server, same account  
> name, same password, and they already entered it when accessing IMAP  
> or POP3).  Then you just tell those that need to send email with  
> outside domains in "from" to make sure "use username and password" is  
> checked in their mail client (if not already checked, some clients  
> default to authenticating to SMTP server).  Hopefully it wouldn't be  
> too much of disruption.

I can relate to Mr. McDonald, telling a few non-technical users to make sure 
"use username and password" is checked is nowhere near as you make it sound.  
Many most likely don't even know how to get into their mail settings.

Pop-before-smtp might save you a lot of trouble.  It's a small program to 
auto-populate and remove (after a set time) IP's from a separate sendmail 
access DB that are pulled from the pop authentication logfile.  That way, as 
long as a user has popped mail within 15 minutes or so, they are OK to send 
through the server.

Karan's repo (http://centos.karan.org/) has a package built from Fedora 

- Kevan Benson
- A-1 Networks