Migrate 1K mailbox to 365 Exchange

network.sudo 0 Reputation points

Hello ,

i have 1K mailbox working on-prmies with icewarp product , we planing migrate to 365 , already user synced , already have license , and no issue to migrate mailboxes from IMAP to 365 ,

but the issue is that gab from currently email still receiving and if go to change mx record and full dns migrate will interrupted the company issues which it's critical ,

is there any solution or recommendation to fill gab and migrate without lose any email or service interrupted while migration , like keep receiving and sending email for both environment until finish the migration


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  1. Aholic Liang-MSFT 13,731 Reputation points Microsoft Vendor

    Hi @S.zw

    Before you delete the migration batch, the source email system is synchronized with Microsoft 365 or Office 365.Therefore, you don't have to worry about losing messages after MX points to M365.

    For more information, please refer to steps 5 and 6 in this link:

    Migrate other types of IMAP mailboxes to Microsoft 365 or Office 365 | Microsoft Learn

    Hope it helps you!

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  2. Amit Singh 4,766 Reputation points
    0 comments No comments

  3. Filip Korbel 0 Reputation points

    Hi S.zw, I am interest to know what was driving your decision to migrate from IceWarp. Thanks