[CentOS] Replacing Qpopper with Dovecot

I currently have a Centos server with Sendmail and Qpopper supporting about
50 mail users.  I am planning to replace Qpopper with Dovecot to allow some
users to have IMAP access to their mail (others will still use POP3.)  Is
there anything special to be aware of in setting up this migration?

Thanks for your comments.

Gerald