Links to MS Teams 3rd party app are being changed by outlook

Copper Contributor

Hi, users of our 3rd party Teams App are getting strange behavior with direct links to our Teams App, when viewing in Outlook.

The link we send them is a deeplink to our MS Teams 3rd party app, which is generated based on this documentation

For most of our users, this is not an issue. However, with one client the following happens:
- In the email, the link inside a styled <a> tag is NOT the deeplink we send, (, but is instead a link to our marketing website, somehow ( When hovering over the link initially, Outlook says "Original URL:". The strange workaround is right clicking the link, hovering away, and hovering back changed the link back to the deeplink we want, and it correctly links the user to MS Teams. The affected user is using Outlook on desktop, Windows OS.

Working with their IT team, they did some work to allow wildcard matches to be allowed through some safe link configuration, but the issue still persists as above.

Can you please let us know what Outlook or Microsoft cloud security setting would be doing this to our users?

1 Reply
Bumping this up for anyone from Microsoft able to help or at least respond to let us know you've seen this, but no solution yet? Maybe there is a better place to ask this?