Thank you for your feedback, we are aware of the issues with language detection and are actively working on a fix that will again allow automatic spellchecking across multiple languages. Please note that the spell check is still working for the default language (the Teams app language). We will share an update as soon as one is available.
Adding email as a left tab panel remains under review. We are working on adding several Teams and email integrations:
- Share to Teams: Share a copy of an email and any attachments into a chat or channel directly from Outlook
- Share to Outlook: Share a copy of a channel or chat conversation via email directly from Teams
- Actionable Teams Activity Emails: Teams missed activity emails display the latest replies and allow you to reply directly from Outlook
See this post for more information: