Microsoft Quietly Shipped Five Updates This Month — Here's What Actually Matters
Microsoft changes something in Microsoft 365 almost every week. Most of it never reaches the people actually using Outlook, Teams, and SharePoint every day — it's buried in the Message Center, the admin notification feed most businesses never open. A few updates from the last month are worth knowing about, whether or not you ever touch the admin center yourself.
In this roundup
- Free mailbox storage doubled
- Teams can now block uninvited AI bots
- Copilot stops reading stale archived files
- New messaging limits for un-branded tenants
- The slow retirement of an old connection method
1. Your mailbox just got twice as big — for free
Exchange Online
Microsoft 365 Business Basic, Standard, and Premium have all moved from a 50 GB mailbox to 100 GB, at no extra cost. The rollout runs June through September 2026, so if your inbox hasn't grown yet, it's likely still in the queue.
Why it matters: If anyone on your team has hit the "mailbox almost full" warning, this quietly fixes it. The rollout isn't instant or uniform — verify the actual quota per user rather than assume everyone already has it.
2. Teams is finally kicking out uninvited AI notetakers
Teams
An unfamiliar bot joining a call and silently recording is now common — usually because someone once gave a transcription app calendar access. From late August 2026, admins can set a policy that automatically blocks these external bots, instead of relying on whoever's running the meeting to notice.
Why it matters: Confidential meetings have been quietly recordable by apps nobody in the room approved. This closes that gap — but audit who's using a legitimate notetaker first, since a blanket block affects them too.
3. Copilot just got told to stop digging through old files
Copilot & Purview
Microsoft added the ability to archive SharePoint and OneDrive files into lower-cost storage once they've sat untouched through their retention period. The side effect: archived files are no longer available for Copilot to reference or summarise.
Why it matters: It's a two-for-one — storage costs on old files come down, and stale content stops quietly shaping Copilot's answers. A five-year-old draft policy shouldn't influence what Copilot tells someone today.
4. A leash on companies that never set up a custom domain
Teams
If your organisation still uses the default onmicrosoft.com domain in Teams, new outbound external messaging limits begin rolling out from mid-September 2026.
Why it matters: This is the kind of change that quietly breaks something nobody expected. If your business talks to partners or clients over Teams chat and never set up a custom domain, check now. Adding one is a one-time fix that sidesteps the limit entirely.
5. The slow retirement of an old way of connecting to Exchange
Exchange Online
Exchange Web Services (EWS) — a two-decade-old way for older apps to talk to Exchange Online — begins being disabled by default on 1 October 2026, with full retirement by 1 April 2027.
Why it matters: If your business uses an older CRM integration, custom add-in, or line-of-business app that's "just always worked," there's a real chance it talks to Exchange this way. A five-minute check now beats finding out during a busy week.
The takeaway
Useful and disruptive changes arrive through the same quiet channel. None of these five updates made headlines, and most businesses won't notice any of them — until the day one of them does something unexpected. The only real defence is someone occasionally paying attention on your behalf.
We track changes like these so you don't have to.