Moving mailserver from (Solaris, redhat) to Debian

[Mauricio]

         Quick sendmail/mail question: we have here a E450 which is 
the main file and mailservers.  Now, two users are getting their 
email off another machine, a dell redhat linux box, in the following 
manner:

o /etc/aliases in the E450 sends email for those two guys to 
user at webmail, where webmail is a CNAME for the dell.
o They imap to webmail to check their email.  Everybody else imaps to the E450.
o BTW, their accounts are in the E450; only the mailbox is in the dell.
o Also, currently, the mailboxes in the E450 are in the user accounts 
but then symlinked to /var/spool/mail.  Not my favourite way of doing 
things.

What I would like to do is move those two accounts back to the E450. 
This way, I can install debian (I do not like redneck linux and, on 
the top of that, it was poorly installed.  Conceptually speaking, it 
was a good idea but implemented quite badly) in the dell and get that 
machine as our mailserver. Here is how I propose to do it:

o Move the mailboxes to the E450
o Edit /etc/aliases so mail is kept in the E450 instead of forwarded 
to the webmail.  Then, run newaliases and restart sendmail just in 
case...
o Edit the CNAME webmail record to point to the E450

Should that suffice?  If so, after the dell is back as debian and I 
have mail/spamassasin/etc running, I would

o Stop sendmail in the E450 so we do not lose emails
o Move the mailboxes to the dell
o Change the webmail CNAME back to the dell.  Probably I should just 
change the mail CNAME to the dell so everybody's mailclients start 
looking for those emails in that machine. Changing two people from 
checking at webmail to mail is quick.
o Change the MX record to send mail to the dell
o See if crashes

Comments on my madness? Also, I would like to use cyrus in the debain 
box (we currently are using wu-imap). My main concern is that I know 
how to repair a mbox file as needed but do not know what to do if a 
maildir file gets corrupted.  How often such problem happens and how 
easy is it to fix?
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