Cutover Exchange Online migration from any IMAP email system | IT Partner

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Cutover Exchange Online migration from any IMAP email system

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  • Duration: 1 week;
  • Price: $90 + $10 per mailbox;
We will migrate users, email data and email folders from any IMAP system to Office 365 / Exchange Online.
  1. IT Partner is responsible to
  2. Client is responsible to
  3. Out of the scope of this project (additional cost items)
  4. Prerequisites
  5. Plan
  6. Results

We use the Internet Message Access Protocol (IMAP) to migrate your email from Gmail, Exchange,, and other email systems that support IMAP protocol for email access. When we migrate the user’s email by using IMAP migration, only the items in the users’ inbox and other mail folders are migrated. Contacts, calendar items, tasks and other items cannot be accessed via IMAP protocol and cannot be migrated through this process. If you have such items in your email client, such as Outlook, you can migrate them manually. We will provide guidance and support in that process, if needed.

Our objective is a full migration of all mailboxes from the source IMAP system. Only users, emails and email folders are migrated. A migration project will be considered successful if all mailboxes are moved to Office 365 without downtime or lost data and with minimal user disruption.

IT Partner is responsible to

  • Hold a kickoff meeting to exchange contact info, plan milestones and discuss the project.
  • Provision new Exchange Online mailboxes by creating Office 365 user accounts and assigning Exchange Online user licenses.
  • Add and validate email domain(s) to Office 365
  • Start an IMAP migration batch.
  • Provide a report with the number of mailboxes that were successfully migrated and how many, if any, could not be migrated.
  • Configure the post-cutover mailbox synchronization called incremental synchronization to pick up and sync any emails being delivered to the source IMAP system after the cutover.
  • Resolve any migration issues and errors to ensure that all IMAP mailboxes have been successfully migrated
  • Plan and guide the cutover from the source system to Exchange Online.
  • Monitor DNS changes as they propagate over the Internet.
  • Monitor the health and status of the destination Exchange Online environment to make sure everything is all right.
  • Delete the migration batch after migration is completed and Incremental sync has stopped.

Client is responsible to

  • Create an Excel spreadsheet that contains a row for each user whose IMAP mailbox will be migrated and provide necessary data about users being migrated.
  • Provide a dedicated point of contact responsible for working with IT Partner and coordinate any outside vendor resources and schedules.
  • Configure all networking equipment such as load balancers, routers, firewalls, and switches.
  • Provide access to physical and virtual servers and/or systems and services as needed. Provide needed remote and/or physical access to facility and systems required to complete work.
  • Perform changes to internal and external DNS, as required.
  • Assist with identification of high risk users (top executives and VIP-users, users with mailboxes 50 GB or larger and/or deleted folders 30 GB or larger).
  • Ensure IMAP Access is enabled for all users.

Out of the scope of this project (additional cost items)

  • Informing users about the migration
  • Training of customer team (could be added as additional service)
  • Migration of Corporate documents to SharePoint Online (could be added as additional service)
  • Desktop software settings

Upon completion of the engagement, we will provide a Project Closeout Report. This document will indicate final project status including evidence of meeting acceptance criteria, outstanding issues and final budget. If you want more extensive documentation - this can be provided for an additional fee.


  • You must have a destination Office 365 tenant with Exchange Online licenses available.
  • You must have admin-level access to your email domain DNS zone.
  • You must have a source IMAP system with either admin-level access OR with access to individual user mailboxes.


May vary depending on your needs.

  1. Kickoff meeting
  2. Pre-migration source system health check
  3. Create users or configure AD connect tool
  4. Start email migration
  5. Verify email migration
  6. Change MX record to new Office 365 tenant
  7. Final email migration
  8. Post-migration tasks


  • Users can access Exchange Online from their desktop PC’s, mobile phones and tablets from any place, any time
  • Your mail server is successfully migrated to the new tenant Office 365 and is accessible by all users
  • All necessary Transport rules are created and working
  • Mail flows flawlessly to and from Exchange Online
  • Exchange Online Protection is configured and working