Upgrading from 4.37 (I know, I know, it's OLD)

[Diane Rolland]

I want to upgrade my older MailScanner version to (probably) the latest
stable.
 
I would be using the rpm installation for RedHat.  So, normally, I'm
comfortable with that type of upgrade.
 
My concern is that since my version is SO old, is there anything I need to
look out for in upgrading to the latest?  I'm using pretty standard rulesets
(whitelist, blacklist, archive, non.spam.actions).

So, any insights on what I should look out for would be greatly appreciated.
 
For those of you who also subscribe to mailwatch-users, you are probably
laughing out loud at my question...  My mailwatch upgrade from 0.5.1 --> 1.0
--> 1.03 on my MailScanner 4.37 version wasn't exactly smooth...  My
GREATEST THANKS goes to Steve Freegard who helped me through it.  Steve, you
ROCK!
 
Thanks,
Diane

p.s.  And, yes, I do have the book; (I've purchased the last two revisions).