I use outlook.live webmail and can access it either via a browser (I always use Edge) or via the W11 mail app. Yesterday I find that I'm getting a single email (an ad) every time I open the browser version. If I delete the email (and there is no way to delete it without opening it) then another single ad immediately replaces it. And so it goes on.
If I open the W11 mail app then these ads are not visible.
(This only started happening yesterday and coincidentally an MS pop up window appeared yesterday saying something like 'do you want Outlook to open links'. I've had that appear in the past and ignored it as I don't know quite what it is offering. Links in emails open anyway when clicked unless the email is classed as spam and then Outlook blocks opening. So this may or may not be related... just mentioning it in case)
This is how it looks in a browser. If I look using the app then I don't see any trace of these ads.

If I open the W11 mail app then these ads are not visible.
(This only started happening yesterday and coincidentally an MS pop up window appeared yesterday saying something like 'do you want Outlook to open links'. I've had that appear in the past and ignored it as I don't know quite what it is offering. Links in emails open anyway when clicked unless the email is classed as spam and then Outlook blocks opening. So this may or may not be related... just mentioning it in case)
This is how it looks in a browser. If I look using the app then I don't see any trace of these ads.

My Computer
System One
-
- OS
- W11 Pro x64 24H2 Dev
- Computer type
- Laptop
- Manufacturer/Model
- Dell 7760 Mobile Precision 17"
- CPU
- Intel i5
- Motherboard
- Unknown
- Memory
- 8Gb
- Graphics Card(s)
- Intel HD Graphics
- Sound Card
- Realtek
- Monitor(s) Displays
- Internal
- Hard Drives
- 2 x 256Gb SSD
- PSU
- Dell 240 watt
- Mouse
- Dell Premier Bluetooth
- Internet Speed
- 50Mbps
- Browser
- Edge
- Antivirus
- Default Microsoft Security