OK, I ditched the Fedora and went with CentOS..ever glad I did! I have searched Redhat manuals and Google and all resources (even the Redhat manuals) only discuss users and groups on a single server.

Quick comparison question:

I have been ALL MS for nearly ten years so I am use to having Active Directory be the 'central' place for authentication for users/passwords/email addresses..etc.

Now that I am moving my hosting environment into a Linux server setup, I want to have Postfix (SMTP) on one server and Dovecot (pop3/IMAP) on another server to alleviate the possible congestion of having everything on one server.

How do I then manage the user accounts between multiple servers since BOTH Postfix and Dovecot will need to authenticate users? Does Linux have something similiar to Active Directory?

I can not forsee having to maintain separate user/passwd files on both machines...

Any good tutorials on this or am I going after this the wrong way and should keep smtp/pop3 on the same server...

(Brand new to Linux so PLEASE forgive the question if I missed something basic in my learning the past few months)

My gratitude for your time and patience...

InTech

Dear In Tech.

i will tell you that, you can configure postfix + mysql
means virtual hosting with postifix,
with this configuration you can handle as many users as you wish, without any prob.
and also you can configure squirrelmial and calmv, so no prob. of spam.
and you have very nice setup.

so just use virtual hosting with postfix. just go through www.postfix.org and in document section use link virtual domain hosting.

Many isp in world are using this thing.
so nwo i hope that you also use it and enjoy it.

Thanks.
With Warm Regards,
Ashish Barot.

Probably you should go with the clean solution that linux-india proposed. (Similar setups (mail addresses not linked to OS users) are possible with qmail too.)

But to answer your question,
Yes, Unix has NIS (network information service). It's the old Yellow Pages (yp), which had to be renamed for legal/trademark reasons. It's a good idea, particularly when you share file systems using NFS (network file system).