In-Place Archive Migration — Microsoft 365 Archive Mailbox Move
In-Place Archive Migration moves Exchange archive mailboxes from Exchange Server or Exchange Online to Microsoft 365, with archive data placed alongside the appropriate destination mailboxes. Archive moves use Microsoft's native Exchange migration tooling — mailbox moves via the Exchange admin center and Exchange Management Shell from on-premises Exchange, and cross-tenant mailbox migration batches, which support archive mailboxes, between tenants. The service is $10 per mailbox plus an $800 tenant fee, over 7 days, and completes when all in-scope archive mailboxes have been moved and verified.
What this engagement is
In-Place Archive is Microsoft Exchange's long-term email storage capability. It gives users an archive mailbox for historical messaging data outside the primary mailbox and reduces reliance on personal store (.pst) files. When organizations move to Microsoft 365 — or between Microsoft 365 tenants — the archives must move too, and Microsoft's native tooling supports it: from on-premises Exchange, archive mailboxes are moved with the Exchange admin center (EAC) and Exchange Management Shell; between tenants, cross-tenant mailbox migration batches support archive mailboxes with primary- or archive-scoped moves. Two realities shape planning: large archives are throughput-bound — transfer speed depends on item counts, Microsoft service throttling, and source condition rather than a fixed rate — and auto-expanding archives have practical limits on how their extended content moves, which IT Partner assesses during discovery. The project is considered complete once all in-scope archive mailboxes have been moved, associated with the correct destination mailboxes, and verified.
Success criteria
What you receive
How the work unfolds
Confirm the archive migration scope, source and destination environment details, mailbox list, success criteria, customer contacts, escalation path, communications approach, expected schedule, and any high-risk or VIP users requiring additional coordination.
Review source archive mailbox inventory, licensing readiness, tenant and Exchange connectivity, permissions, DNS-related dependencies if applicable, mailbox/archive status, and migration readiness items that could affect archive data transfer.
Configure the required migration approach and begin the archive mailbox migration or pre-stage activity using Microsoft-supported Exchange tools and administrative interfaces, while monitoring initial batch behavior and resolving blocking issues.
Validate migration progress and results by checking migration batch status, archive mailbox availability, destination mailbox/archive association, item counts where available, and a representative set of migrated archive data.
Complete the final migration activities for remaining archive mailbox data, monitor completion status, address failed or stalled items within the agreed scope, and confirm that archive data is placed with the appropriate destination Microsoft 365 mailboxes.
Perform post-migration validation, review any remaining exceptions with the customer, confirm acceptance against the stated success criteria, and prepare the project closeout report with final status, outstanding issues, and budget information.
Prerequisites
Who does what
IT Partner
- Discover and assess In-Place Archives from the source tenant.
- Perform pre-stage migration.
- Assign the licenses.
- Start and control the final In-Place Archive migration.
Your team
- Provide a dedicated point of contact responsible for working with IT Partner.
- Coordinate any outside vendor resources and schedules.
- Configure all network equipment, such as load balancers, routers, firewalls, and switches.
- If Microsoft Outlook or other desktop email clients are used to connect to Microsoft 365, deploy email software on client workstations.
- Perform changes to internal and external DNS, as required.
- Assist with identification of high-risk users (top executives and VIP users, users with 50 GB mailboxes or larger and/or 30 GB deleted folders or larger)
- Recreate a new Outlook profile on all client workstations if the desktop Outlook version is used.
- Inform users about upcoming changes and provide the necessary information.
What's not included
Limitations & technical notes
Frequently asked questions
What does IT Partner's In-Place Archive Migration service do?
It moves Exchange archive mailboxes from Exchange Server or Exchange Online to Microsoft 365, placing archive data with the appropriate destination mailboxes. The project completes when all in-scope archives have been moved and verified.
What is an In-Place Archive in Exchange?
An In-Place Archive is Microsoft Exchange's long-term email storage capability — an archive mailbox for historical messaging data outside the user's primary mailbox. It helps organizations reduce reliance on personal store (.pst) files.
How are archive mailboxes actually migrated?
With Microsoft's native Exchange migration tooling. From on-premises Exchange, archives move via the Exchange admin center and Exchange Management Shell; between Microsoft 365 tenants, cross-tenant mailbox migration batches support archive mailboxes, with moves scoped to the primary, the archive, or both.
How much does the In-Place Archive Migration cost, and how long does it take?
The service is $10 per mailbox plus an $800 tenant fee, over a 7-day engagement, quoted in writing before work begins. Very large archives can extend the timeline because migration is throughput-bound — this is confirmed during discovery.
What is included in the service?
Discovery and assessment of the in-scope In-Place Archives, pre-stage migration, license assignment, the final archive migration started and controlled by IT Partner, and a project closeout report with final status, acceptance criteria matching, outstanding issues, and the final budget.
What prerequisites are required before the archive migration can start?
Administrative access to the source environment (global admin for a Microsoft 365 tenant, or Exchange administrative access on-premises), global admin access to the destination Microsoft 365 tenant with Exchange Online licenses and archive entitlements available, and access to your email domain DNS zone.
Do large or auto-expanding archives migrate differently?
They can. Migration speed is bound by item counts and Microsoft throttling rather than a fixed rate, so large archives take longer, and auto-expanding archives that have grown into auxiliary storage have practical limits that IT Partner assesses during discovery. Both are planned rather than discovered mid-project.
Who assigns Microsoft 365 licenses during the migration?
License assignment is part of IT Partner's scope for this service. The client ensures the destination tenant has the required Exchange Online licenses available, since archive mailboxes require appropriate archive entitlements in the destination.
Does IT Partner migrate PST files as part of this service?
No — this service migrates Exchange In-Place Archive mailboxes. PST discovery and import is a separate scope, though moving archives to Microsoft 365 is a common step in reducing PST reliance going forward.
Will there be downtime during archive migration?
Archive data is pre-staged while users keep working, and the final migration is coordinated with your schedule. The service does not promise a zero-impact cutover; expected timing and any user-visible effects are reviewed at kickoff.
What does the customer need to do during the migration project?
Provide a dedicated point of contact, coordinate outside vendors, configure network equipment where needed, perform required internal and external DNS changes, help identify high-risk users (VIPs, 50 GB+ mailboxes, 30 GB+ deleted-item folders), deploy desktop email software and recreate Outlook profiles where desktop Outlook is used, and inform users about upcoming changes.
What happens after the archive migration is completed?
IT Partner delivers a project closeout report with final status, acceptance criteria matching, outstanding issues, and the final budget. The migration is complete when all in-scope archive mailboxes are moved, associated with the correct destination mailboxes, and verified. More extensive documentation is available for an additional fee.