Yes, it was a version problem.
For anyone else who experiences the following error using ATRPMS repo for dovecot:
May 6 17:12:31 drizzle dovecot: dovecot: Created login processes successfully, unstalling
May 6 17:12:31 drizzle dovecot: managesieve-login: Fatal: Dovecot version mismatch: Master is v1.2.11, login is v1.2.10 (if you don't care, set version_ignore=yes)
May 6 17:12:31 drizzle last message repeated 2 times
May 6 17:12:31 drizzle dovecot: dovecot: Temporary failure in creating login processes, slowing down for now
Here are the steps to correct:
# yum install dovecot-devel dovecot-sieve-devel
# wget
http://dl.atrpms.net/all/dovecot-manages..._4.src.rpm
# rpmbuild --rebuild dovecot-managesieve-0.11.11-0_4.src.rpm
# yum remove dovecot-managesieve
!! yum upgrade will not work because atrpms package is same version, so remove it.
# cd /usr/src/redhat/RPMS/x86_64
# yum --nogpgcheck install dovecot-managesieve-0.11.11-0_4.x86_64.rpm
# service dovecot restart