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Please kindly understand that the Outlook tag here we mainly focus on general issues about Outlook desktop client. As far as I know, HTML formatting can be set in Outlook to avoid links rendering text formatting. Please follow these steps: In Outlook, go to File > Options > Mail> Compose messages.
If that doesn't work, it’s recommended to post your question in the following dedicated forum for Dynamics 365: https://community.dynamics.com/.
Hope this helps!
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