Brand new MailServer opportunity

I know this is a loaded question - forgive me.
a Unix Veteran, have inherited sendmail servers before. (vi conf files). but never established from the ground up. I have a green field opportunity - AND I am thinking it would be nice to use a web based mail admin tool..(and also dns server support) on RHEL5 so...

This is for application alert support so no outlook stuff at all. The app doesn't need any API (like php, sql..etc..) Just email message alerts. I kind of prefer no need for mysql. This is for a NOC in a small part of a giant corp.

Simply need:
smtp server, private relay, inbound IMAP or POP, option for TLS, spam-blockin (maybe spamassassin), and procmail rules - this system will also be the DNS server

choices
sendmail - webmin
postfix - webmin
postfix - ispconfig (buts not debian)
Cpanel? - (doesn't seem so)
other?

I would just like to put a nice wrapper around the configs for the admin - in that way he/she also gets fields-to-fill-in to remind them of necessary and optional configs etc...

I actually know sendmail a bit and never used postfix but being that its newer is making me think postfix. I have sandboxed with Webmin but I see ispconfig is pretty powerful, although I am not setting up Multiserver (for HA maybe I should)

Please Please if you were a seasoned admin - had a brand new project - prefer no low level file edit config - want the same gui for DNS, MAIL, (and maybe LDAP services) - What toolset would you use?

Sorry if this a loaded question - I did search google and this site for a couple hours and thought it was time to post.

I run ispconfig3 on Fedora 13. It may be overkill for what you want, but ispconfig3 sets up a nice virtual user email server (among other ispconfig features) .

Thank you for your reply - There IS discussion out there about this.

In summary:
ISPConfig friendly but is full LAMP and alters low level config "files" / authetication etc...
Webmin - "helper/not as friendly" to a knowledgable sys admin BUT! leaves open to direct manual file editing as normal linux. As in before there were GUI control panels

If my summary is incorrect please let me know..

Thank you