first time post, and I did not find answers after search the forum.

any reason why zimbra not using cyrus or dovecot as IMAP/POP/LMTP server

I did not find answer from the forum. but I am guessing it is because the mailbox server integrate both the IMAP/POP/LMTP server and the index/search/UI, so instead of integrating them together, zimbra just develop their own.

Thanks for your answers.