dovecot pre-install issue

[soumitri at iitk.ac.in]

Hello all,

I am going for a dovecot director based setup (2 director+ 2 imap), more 
imap servers will be added later  depending on demand/load. Presently I 
have 12000+ dovecot users with Maildir quota varying from 1 GB to 20GB. 
(peak hour IOPS 50000+)

I am having 2 options in choosing dovecot version.

1) Old stable release. I.e RHEL, with prebuilt binary. This will be 
having less trouble in managing. Why RHEL still using version 2.2.10.

2) Latest release with best features and lesser known bugs. I.e CentOS7 
with with latest compiled version. I have to be more involved if a bug 
is found.

I will prefer a less admin work after the setup, with all/most features 
working.

If you have a recent similar setup/dovecot gurus, Pl. suggest.

With thanks & regards,

-- 

Soumitri Mishra
http://home.iitk.ac.in/~soumitri/