Oct 11 2017 11:41 PM - edited Oct 11 2017 11:42 PM
Oct 12 2017 01:34 AMSolution
Oct 12 2017 01:23 PM
I addition to the other responses I'll like to provide you with a link to the Office 365 mail migration advisor as well as one for Onboarding and set up guidance.
Office 365 mail migration advisor
Deployment advisors for Office 365 services
Oct 13 2017 03:10 AM
You can also check out CodeTwo Office 365 Migration: https://www.codetwo.com/office-365-migration/?sts=6652 to migrate emails from Zimbra to Office 365 via IMAP. Just make sure IMAP is enabled on the source server, and you have a list of users' credentials to access the source mailboxes.
If you would like to give it a try, here you can download a free trial version: https://www.codetwo.com/office-365-migration/download?sts=6652.
If you have any questions about CodeTwo Office 365 Migration, give me a shout.
All the best,
May 01 2019 12:44 PM
We do not allow links to third-party tools to keep this place informative and as spam-free as possible. Since it was asked, you may recommend third-party tools, but if you are recommending only a single tool, it must be clear that you are associated with the product.