01
Discovery
Mailbox count and sizes, shared mailboxes, archives, file shares, DNS, devices and integrations, written into one inventory.
FIG 01 · Microsoft 365 Migration
Office 365 migration services without lost mail or surprises
A migration plan in plain English: the right method for your mailbox count, a pilot group first, and the licenses you need, not the ones a reseller wants to sell.
See how it works
FIG 02 · Quick answer
What are Office 365 migration services?
Office 365 migration services move your email, calendars, files and users into Microsoft 365. Elgrith plans cutover, staged, hybrid or IMAP moves from Exchange, Google Workspace or another tenant, tests a pilot group first, avoids licenses you don’t need, and hands over admin access, documentation and licenses in your name.
- A test group moves before everyone else
- Pilot first
- Projects delivered since 2015
- 1,000+
- Clients across the USA, UK and India
- 250+
- Your tenant, admin roles and licenses
- 100%
FIG 03 · Why it matters
Most migration surprises are in Microsoft’s own documentation.
Three rules from Microsoft Learn and the Microsoft Lifecycle site, checked 24 Oct 2026. We plan around them before the first mailbox moves.
01
150
Users Microsoft calls “more reasonable” for a cutover
Cutover migration can move up to 2,000 mailboxes, but Microsoft says it’s more reasonable to migrate 150 users or fewer that way, because of the time it takes.
Source: Microsoft Learn, Ways to migrate multiple email accounts to Microsoft 365 (13 Jul 2026)(opens in a new tab)02
No exceptions
A paid license for every cross-tenant user
Tenant-to-tenant moves need a per-user, one-time-fee Cross Tenant User Data Migration license. Migrations fail without it, and Microsoft doesn’t offer exceptions.
Source: Microsoft Learn, Cross-tenant mailbox migration (26 Mar 2026)(opens in a new tab)03
14 Oct 2025
Exchange 2016 and 2019 left support
Extended support for Exchange Server 2019, and 2016, ended on 14 Oct 2025 (US time). Exchange Server Subscription Edition is the supported on-premises path.
Source: Microsoft Lifecycle, Exchange Server 2019 (checked 24 Oct 2026)(opens in a new tab)
FIG 04 · Methods
Choosing a method: cutover, staged, hybrid or IMAP
Microsoft supports several ways to move mailboxes. The right one depends on where your mail lives today, how many mailboxes you have and how long both systems must run side by side. From Microsoft Learn (13 Jul 2026), checked 24 Oct 2026.
| Method | Use it when | What moves | Watch out for |
|---|---|---|---|
| Cutover or Express | Exchange 2003 to 2013 with fewer than 2,000 mailboxes; Microsoft calls 150 or fewer more reasonable | Mail, calendars and contacts, all at once | Everyone switches in one window |
| Staged | Exchange 2003 or 2007 with more than 2,000 mailboxes | Mail, calendars and contacts, in batches | Only for very old Exchange versions |
| Hybrid | Exchange 2010 with 150 to 2,000 mailboxes, small batches over time, or Exchange 2013 or later | Mailboxes moved gradually while both systems run | More set-up: directory sync and hybrid configuration |
| Google Workspace batches | Moving from Gmail and Google Calendar | Mail and rules, calendar and contacts | Disable retention and archival policies first |
| IMAP | Other hosts that only offer IMAP | Mail folders only; no contacts, calendars or tasks | Mailboxes must be created first; calendars move separately |
| Cross-tenant | Mergers, divestitures and rebrands between Microsoft 365 tenants | Mailboxes, and OneDrive with the same license | Paid per-user license, no exceptions |
Large PST archives can go through Microsoft’s PST Import Service instead of user uploads.
Weighing the platforms first? Google Workspace vs Microsoft 365 in 2026FIG 05 · What you get
What our Microsoft 365 migration services cover
Everything from the first mailbox count to switching off the old system, with users told what changes and when.
02
License plan
Which Business, Enterprise or Frontline plan each person needs, so you don’t buy features nobody uses.
03
Identity
Users, groups and sign-in in Microsoft Entra ID, with Entra Connect sync from on-premises Active Directory where needed.
04
DNS, MX and Autodiscover
Domain verification, MX cut-over, Autodiscover, SPF, DKIM and DMARC, timed to avoid bounced mail.
05
Mailboxes, calendars and contacts
Migration batches from Exchange, Google Workspace, IMAP or another tenant, with delta passes before cut-over.
06
Archives and PSTs
Online archives, PST imports and retention settings, so old mail stays searchable.
07
OneDrive and SharePoint
Personal files to OneDrive and team files to SharePoint, with our SharePoint consulting team for intranets and complex sites.
08
Teams
Teams and channels set up around how people work, with guest access and naming rules agreed first.
09
Devices and Outlook
Outlook profiles, mobile mail apps and device settings updated with clear steps for users.
10
Training and decommissioning
Short guides for users, an admin hand-over, then the old system switched off only after checks pass.
Deliverables
11
deliverables, in writing
Included in every build, written into your fixed quote before work starts.
FIG 06 · Sources
Where you’re moving from
Every source has its own tools and traps. We pick the method per source and test it on a pilot group before the rest of the company moves.
- Google Workspace
- Exchange Server
- Another tenant
Pilot group, then batches
- Exchange Online
- OneDrive
- Teams
Google Workspace to Microsoft 365
- How
- Automated batches in the Exchange admin center move mail and rules, calendars and contacts
- First
- Disable retention (MRM) and archival policies, as Microsoft strongly recommends, so items aren’t flagged as missing
On-prem Exchange to Microsoft 365
- Why now
- Exchange 2016 and 2019 extended support ended on 14 Oct 2025
- How
- Cutover, Express or hybrid by version and size; Exchange Server SE if some mail must stay on-premises
IMAP and hosted mail
- How
- IMAP migration batches into mailboxes we create first
- Limits
- IMAP moves mail only; calendars and contacts are exported and imported separately
Tenant-to-tenant
- When
- Mergers, acquisitions, divestitures and rebrands
- Needs
- Cross Tenant User Data Migration licenses and an organization relationship between tenants
File shares and drives
- From
- Network drives, Google Drive or Dropbox
- To
- OneDrive for personal files; SharePoint sites for team files, with our SharePoint team
Forms and workflows
- From
- Old InfoPath forms, scripts or Google Apps Script
- To
- Power Apps and Power Automate, built by our Power Platform team
FIG 07 · Tenant to tenant
Tenant-to-tenant migration
When two companies merge, split or rebrand, mailboxes and files move between Microsoft 365 tenants. It is the most planning-heavy migration type.
04principles
Cross-tenant licenses
Every migrating user needs a Cross Tenant User Data Migration license, a one-time per-user fee that also covers OneDrive. Microsoft doesn’t offer exceptions (Microsoft Learn, 26 Mar 2026).
Organization relationship
Both tenants are configured to trust each other for mailbox moves, with an admin on each side and a defined migration scope.
Domain cut-over order
A domain can live in only one tenant, so we plan when it is removed from the source and added to the target, and what users see in between.
Identity matching
Target users prepared with matching attributes before mailboxes move, so sign-in, mail flow and shared calendars keep working.
FIG 08 · Continuity
Avoiding downtime and lost mail
We plan to keep disruption small and visible, not to promise zero. These are the safeguards.
05principles
Pilot group first
A small group of real users moves first, so problems surface before the whole company moves.
MX cut-over windows
DNS changes scheduled for a quiet period, with record lifetimes lowered in advance so mail reroutes quickly.
Delta passes
Incremental syncs after the first copy, so mail that arrives during the move is picked up before cut-over.
Rollback plan
Written steps to route mail back if a cut-over goes wrong, agreed before the window starts.
Item-count checks
Source and target item counts compared per mailbox, with retention policies paused so missing items mean real gaps.
FIG 09 · Licenses
Licenses and the July 2026 price change
Microsoft changed Microsoft 365 packaging and pricing from 1 Jul 2026 (announced 4 Dec 2025). In USD list prices, Business Basic went from $6.00 to $7.00 and Business Standard from $12.50 to $14.00. Pick the plan before the move, not after.
04principles
Right plan per person
Frontline staff, office staff and admins often need different plans. We map each role to the smallest plan that covers it.
Plans without Teams
Microsoft also lists suite plans without Teams, at different prices from the plans with it. We check whether one fits how you work.
Licenses in your name
Licenses sit in your tenant and billing account, bought directly or through the reseller you choose.
Compare before you commit
Our 2026 comparison covers Google Workspace and Microsoft 365 plans side by side.
Google Workspace vs Microsoft 365
FIG 10 · After the move
After the move
A migration ends with a secure, documented tenant, not just mail in new mailboxes.
05principles
Security defaults and MFA
Multifactor authentication for everyone, admin roles kept to the few who need them, and legacy sign-in blocked.
Backups
Microsoft runs the service; protecting your data is a shared responsibility. We set up retention and, if you want, a third-party backup.
Windows 10 devices
Microsoft 365 Apps keep getting security updates on Windows 10 until 10 Oct 2028 (Microsoft Learn, 27 Jul 2026). We plan the move to Windows 11 alongside.
Ongoing admin
User changes, licensing and security reviews from our managed IT services team.
IT servicesBuilt by the team behind our flagship
Kenerate AI, our flagship build, designed and engineered by Elgrith. It is an AI image and video studio, not a Microsoft 365 migration project.
See Kenerate AI
FIG 11 · Measurement
What we measure during a Microsoft 365 migration
Every mailbox accounted for, every user able to work. That is what we report, batch by batch.
| How we measure it | What we won’t do | |
|---|---|---|
| Completeness | Item counts per mailbox, source vs target, after each batch | Call a batch done before the counts are checked |
| Mail flow | Test messages in and out after every DNS change | Change MX records outside an agreed window |
| User readiness | Pilot feedback and help requests per batch | Move everyone before the pilot group signs off |
| Security | MFA coverage and admin role count at hand-over | Leave shared admin accounts behind |
| Disruption | Planned and unplanned mail outages during cut-overs | Promise “zero downtime” or “zero data loss” |
We agree the measures, batch plan and cut-over windows in your written scope.
FIG 12 · Process · 6 steps
Pilot first, then move in batches
Free call, discovery, fixed written quote, then a pilot group and batches shown in weekly check-ins, with a rollback plan for every cut-over.
- Step 01
Free call
Tell us where your mail and files live today, how many people you have and what must not break. We ask about deadlines, mergers and devices first.
- Step 02
Discovery
Discovery: mailbox and file inventory, DNS, identity, devices, licenses and integrations, then a method chosen per source.
- Step 03
Fixed written quote
A written scope and a fixed quote, with the timeline, access and hand-over agreed before any work starts. You own the code and IP, and your tenant, admin roles and licenses stay in your name.
- Step 04
Sprints with weekly demos
Identity, DNS preparation and a pilot group first, then migration batches with delta passes, each reviewed with you weekly.
- Step 05
Launch
MX cut-over in an agreed window, final delta sync, item-count checks and user guides on the day.
- Step 06
Support
Old system decommissioned after checks pass, then ongoing admin or a hand-over to your team, as agreed in your written scope.
FIG 13 · What you get
Everything included
Written into your fixed quote, so you know exactly what you are paying for before work starts.
11items
- Written scope and fixed quote
- Mailbox, file and device inventory
- License plan per role
- Migration method per source
- Identity set-up in Entra ID
- DNS, MX, SPF, DKIM and DMARC plan
- Pilot group and batch schedule
- Item-count reports per batch
- Rollback plan for every cut-over
- User guides and admin hand-over
- Your tenant, admin roles and licenses stay in your name
FIG 14 · Tech & tools
The tools behind the work
Proven, well-supported tools, chosen for your project and set up in accounts your business owns.
- Microsoft 365
- Exchange Online
- Exchange admin center
- Microsoft Entra ID
- Entra Connect
- OneDrive
- SharePoint
- Microsoft Teams
- Exchange Online PowerShell
- Microsoft Graph
- PST Import Service
- Intune
- Google Workspace
- Exchange Server SE
FIG 15 · Who it’s for
Microsoft 365 migrations for teams that can’t stop working.
Same method everywhere: discover first, pilot first, check every batch.
4 audiences
Small business
Off Gmail or an old host, onto Microsoft 365.
A simple, planned move for teams of a handful to a few hundred people, with mail, calendars and files moved and everyone shown what changes.
- Right plan per person
- Pilot group first
- DNS done for you
- Short user guides
Mid-size
Exchange servers out of support.
Exchange 2016 and 2019 are out of extended support. We move you to Exchange Online, or plan hybrid with Exchange Server SE where mail must stay on-premises.
- Hybrid where needed
- Entra Connect sync
- Batches by department
- Old servers decommissioned
Mergers
Two tenants, one company.
Tenant-to-tenant moves for acquisitions, divestitures and rebrands, with licenses, domains and identity planned around the deal timeline.
- Cross-tenant licenses planned
- Domain cut-over order
- Shared calendars kept working
- Clear user communication
UK organisations
Microsoft 365 migration for UK organisations.
UK migrations run through our London client-partnership centre, with delivery from our New Delhi HQ. Plans, user guides and documentation are written in UK English, licence choices are checked against UK plan availability, and working hours are agreed in your written scope. For ongoing support, see our London managed IT services.
- London client partner
- UK English guides
- Fixed written quote in GBP
- Your tenant stays yours
FIG 16 · Working with us from the USA and UK
Built in New Delhi. Run on your hours.
Every project gets a point of contact in New York or London and an engineering team in New Delhi. Here is how today’s working days line up, live.
New York
North America
--:--ET
New Delhi team Your working day- Shared working time
- ≈ 3 hours today
- New Delhi is
- 10.5 h ahead
- Live calls, your time
- 9 a.m. to 12 p.m. ET
London
UK & Europe
--:--UK
New Delhi team Your working day- Shared working time
- ≈ 4.5 hours today
- New Delhi is
- 5.5 h ahead
- Live calls, your time
- 9 a.m. to 1:30 p.m. UK
Three ways to work together
- 01
Fixed-scope project
A written scope, one fixed price and a dated plan. Suits websites, apps and MVPs.
- 02
Dedicated team
Designers and engineers on your roadmap every month, billed monthly.
- 03
White label
For US and UK agencies: our work, your brand, unbranded deliverables.
Every engagement
- Fixed quote in USD, GBP or INR after a free 30-minute call
- NDA before discovery. You own all code, designs and content
- A working demo every sprint, not status slides
- Reply within one business day, calls inside your hours
Book a call
Calls on ET or UK hours
FIG 17 · Checklist
Microsoft 365 migration checklist
A short Microsoft 365 migration checklist you can work through before you talk to anyone. We run the full version in discovery.
| Stage | Check | Why it matters |
|---|---|---|
| Inventory | Count mailboxes, shared mailboxes, archives and total data size | Size and source decide the method |
| Licenses | Map each role to a plan; buy cross-tenant licenses if moving between tenants | Cross-tenant moves fail without the license |
| Identity | Clean up old accounts and decide on Entra Connect sync | Duplicates and stale users break sign-in |
| Policies | Pause retention (MRM) and archival policies on the source | Otherwise items look missing after the move |
| DNS | Lower record lifetimes, verify domains, plan MX and Autodiscover | Mail reroutes quickly at cut-over |
| Pilot | Move a small group of real users first | Problems surface before everyone moves |
| Cut-over | Final delta sync, MX switch, item-count checks | Nothing arriving mid-move is lost |
| After | MFA for everyone, admin roles trimmed, backups decided, old system switched off | A secure tenant, not just moved mail |
FIG 18 · Rules and dates
Microsoft 365 migration rules and dates (checked 24 Oct 2026)
Support dates, licensing rules and price changes that affect your migration plan, from Microsoft’s own pages, checked 24 Oct 2026. General guidance from public sources, not legal advice; your counsel confirms what applies to you.
| What changed | When | Source | What it means for you |
|---|---|---|---|
| Exchange Server 2016 and 2019 extended support ended | 14 Oct 2025 (US time) | Microsoft Lifecycle | No more security fixes: migrate or upgrade |
| Exchange Server Subscription Edition in support (Modern Lifecycle Policy) | Since 1 Jul 2025 | Microsoft Lifecycle | The supported path if mail must stay on-premises |
| Microsoft 365 price and packaging update in effect | 1 Jul 2026 (announced 4 Dec 2025) | Microsoft licensing news | Check plans and costs before you move |
| Cross-tenant moves need a one-time per-user license; no exceptions | 26 Mar 2026 | Microsoft Learn, Cross-tenant mailbox migration | Budget for licenses before a merger migration |
| Cutover up to 2,000 mailboxes; 150 or fewer “more reasonable”; IMAP moves mail only | 13 Jul 2026 | Microsoft Learn, Mailbox migration methods | Larger moves need hybrid or batches |
| Google Workspace moves: disable MRM and archival policies first | Checked 24 Oct 2026 | Microsoft Learn, Google Workspace migration | Avoids items reported as missing |
| Microsoft 365 Apps security updates on Windows 10 continue | Until 10 Oct 2028 | Microsoft Learn, 27 Jul 2026 | Plan Windows 11 alongside the migration |
Sources: Microsoft Lifecycle, Microsoft Learn and Microsoft licensing news, all checked 24 Oct 2026. Next check: January 2027.
FIG 19 · Compare
Microsoft’s built-in tools vs third-party migration tools vs users moving their own mail
| Built-in tools (Exchange admin center) | Third-party migration tools | Users move their own mail | |
|---|---|---|---|
| Cost | Included with Microsoft 365 | Per-user tool fees | No tool fees, high staff time |
| Covers | Exchange, Google Workspace, IMAP and cross-tenant batches | Extra sources, file shares and finer scheduling | Whatever each person remembers to export |
| Best for | Most small and mid-size moves | Complex estates or sources the built-in tools don’t reach | A handful of personal mailboxes |
| Risk | Low, with a pilot and item-count checks | Low, but one more vendor to manage | High: missed items and no audit trail |
FAQ
Frequently asked questions
Straight answers about Microsoft 365 Migration with Elgrith.
Microsoft supports cutover (or Express) migration, staged migration, hybrid migration, IMAP migration, Google Workspace batch migration and cross-tenant migration, plus PST imports. Which one fits depends on your source system, Exchange version and mailbox count.
FIG 20 · Related
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Remote-first IT support for NYC teams
Free 30-minute call
Tell us where your mail lives today. We’ll plan the move.
Share your current system, user count and deadline. After a free call you get a written migration scope and a fixed quote.
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