Increased Capacity Means More Storage
How many “your mailbox is almost full” warnings has your team clicked past this year? If you’re on a Microsoft 365 Business plan, those warnings may be about to get a lot quieter.
Microsoft has doubled email storage again. Back in 2013, Office 365 mailboxes jumped from 25 GB to 50 GB. In 2026, Microsoft did it once more: Microsoft 365 Business Basic, Business Standard, and Business Premium now include up to 100 GB of primary mailbox storage per user, up from 50 GB.
The change was part of Microsoft’s 2026 Microsoft 365 packaging and pricing updates, and it rolled out to tenants between June and September 2026. For a lot of small and mid-size businesses, that’s the end of a familiar headache: the one employee who never deletes anything and hits the cap every few months.
Below, we’ll cover who gets the extra space, who doesn’t, what the current limits look like across plans, and what to do before your mailboxes fill all that new room.
Storage increase not for all accounts
The bump applies to three plans: Microsoft 365 Business Basic, Business Standard, and Business Premium. If your users are on one of those, the extra 50 GB arrives as an added storage service plan alongside their existing license. No migration, no new mailbox.
A few accounts don’t see a change:
- Enterprise plans like Microsoft 365 E3 and E5 and Office 365 E3 and E5 already had 100 GB mailboxes, so nothing moves there.
- Standalone Exchange Online Plan 1 licenses can still top out at 50 GB. Microsoft called this out specifically, so it’s worth checking if you bought email separately from the rest of Microsoft 365.
- Frontline plans such as Office 365 F3 stay at 2 GB, since they’re built for workers who don’t live in their inbox.
- Custom quotas set by your administrator stay exactly as they were. If someone capped a mailbox at 20 GB on purpose, the upgrade won’t override it.
One more detail: licenses don’t stack. A user with both a Business plan and an Enterprise license gets the larger of the two limits, not the sum.
Microsoft 365 Mailbox Storage Limits at a Glance
Here’s where the most common plans stand after the 2026 update, based on Microsoft’s published Exchange Online limits:
| Plan | Primary mailbox | Archive mailbox |
|---|---|---|
| Microsoft 365 Business Basic | 100 GB | 50 GB |
| Microsoft 365 Business Standard | 100 GB | 50 GB |
| Microsoft 365 Business Premium | 100 GB | Up to 1.5 TB (auto-expanding) |
| Microsoft 365 E3 / E5 | 100 GB | Up to 1.5 TB (auto-expanding) |
| Office 365 E1 | 50 GB | 50 GB |
| Office 365 F3 | 2 GB | Not included |
| Shared mailbox (no license) | 50 GB | Not included without a license |
The headline number gets the attention, but the archive column is where Business Premium quietly pulls ahead. Auto-expanding archiving has to be turned on by an administrator, so it’s worth confirming it’s actually enabled.
Paying for expanded storage
In 2013, Microsoft made a point of saying the extra storage came with no price increase. This time the story is a little different. The storage boost arrived as part of a broader packaging update, and Microsoft’s updated pricing for many Microsoft 365 plans took effect July 1, 2026 for new purchases and renewals. Existing customers generally see any change at their next renewal date, so it’s worth checking your agreement before that date sneaks up on you.
If 100 GB still isn’t enough for your heaviest users, you have a few options:
- Turn on archiving. Archive mailboxes move older mail out of the primary inbox automatically. Business Premium and Enterprise E3 and E5 include auto-expanding archives up to 1.5 TB.
- Add Exchange Online Archiving. For plans with a 50 GB archive, this add-on extends archive capacity without changing the user’s whole license.
- Move files out of email. Every Business plan user gets OneDrive cloud storage, so sharing a link instead of attaching the same 20 MB file to 40 emails saves a surprising amount of space.
- Revisit the license mix. Some businesses bought E3 licenses purely for the bigger mailbox. With Business plans now at 100 GB, that upgrade may no longer be necessary.
Is Your Mailbox Getting the Upgrade?
The rollout happened in waves, so users in the same company may not have all received the new limit at the same moment. To check:
- In the Microsoft 365 admin center, go to Users > Active users, select a user, and open Licenses and apps.
- Confirm the user has an eligible Business plan and that its included services are turned on.
- Have your IT team confirm the mailbox’s actual quota in Exchange Online.
One caution straight from Microsoft: don’t remove and reassign a license just to force the new limit to appear. Removing a license removes access to its services and starts the data retention clock. If a user is still stuck at 50 GB, it should resolve on its own, and your IT provider can confirm.
Bigger Mailboxes, Bigger Responsibility
More room is great. It also means your team will keep more email, for longer, and that has a few side effects worth planning for.
Search gets slower when inboxes grow, especially on older laptops running Outlook with a local cache. Retention gets trickier, because every extra year of mail is another year you may need to produce for a client dispute, an audit, or a records request. And a mailbox stuffed with invoices, contracts, and client details is a more valuable target if an account is ever compromised.
There’s also a common assumption that Microsoft backs everything up for you. Microsoft keeps the service running, but deleted items are only recoverable for a limited window: 14 days by default, adjustable to 30. If someone deletes a folder in March and notices in June, that mail may be gone.
A bigger mailbox is a good excuse to set clear retention policies, confirm your backups cover Microsoft 365, and tighten up authentication and account hygiene across the team.
LG Networks Can Help You Make the Most of Microsoft 365
A licensing update like this one is good news, but it rarely shows up on its own. It comes with renewal dates, plan changes, and settings that someone has to check user by user. That someone doesn’t have to be you.
LG Networks provides managed IT services in Dallas, TX, and across DFW, including Microsoft 365 licensing and administration, cloud backups for your email and files, cybersecurity, and a 24/7 helpdesk your team can actually reach. We’ll confirm every mailbox picked up its new limit, review whether your current license mix still makes sense after the 2026 changes, and make sure all that extra email is protected and recoverable.
What would your team do with one less “mailbox full” warning to worry about?
Take the first step. We’ve got you covered.
Want a second set of eyes on your Microsoft 365 licensing before your next renewal? Contact Us Today.
