Can I set up my email as Exchange email accounts?

Can I set up my email as Exchange email accounts?

I am thinking of bringing over basically everything to ZOHO, starting with mail first.

Currently my 3 domain email accounts remain as regular IMAP accounts. i would like them a bit more secure and synced as Exchange accounts and letting ZOHO do my hosting as well.

My question is - once I sign up my domain within your mail program, is there an option to them convert my accounts from IMAP to Exchange accounts? Or should I set them up at Microsoft.com first as Exchange accounts.

I am confused here - what is the best way to do this? Furthermore, I want someone to tell me the most secure way to set up my email within ZOHO as I send tons of highly confidential email daily. Is there a way also that I can get an optional encryption feature?

Please advise ASAP and thanks.

Erik