Dear @Justin -,
Thank you for reaching out to Microsoft Q&A forum.
We’re sorry for the inconvenience this behavior has caused, and we appreciate you taking the time to bring this to our attention.
What you’re experiencing is related to Outlook’s Suggested Recipients (Auto-Complete) feature in New Outlook for Windows. When an email address has been used before, Outlook may store it and automatically suggest or reinsert it when you move between fields, such as when pressing the Tab key.
You can stop the incorrect address from appearing by using the following options:
- Open a new email.
- Start typing the incorrect email address in the To field.
- When the address appears in the suggestion list, hover over it and select the X (Remove) icon.
Visit here for more details: Manage suggested recipients in the To, Cc, and Bcc fields in Outlook
We understand how important it is to have a smooth and predictable experience when composing emails, and we agree that improvements in this area would be valuable for many users.
While we’re not able to change the current product design through this forum, we strongly encourage you to share your feedback directly with Microsoft. This is the most effective way to help influence future improvements.
You can submit feedback using one of the following methods:
- In New Outlook for Windows: go to Help > Give feedback
- Or via the Microsoft 365 Feedback Hub:
Go to: Microsoft 365 Feedback Hub > Select Send Feedback > Describe your experience and suggestion in detail.
Sharing your experience through these channels helps the product teams better understand real-world scenarios and prioritize future enhancements.
Thank you again for your patience and for sharing your feedback. If you have any other questions about the current functionality, please don’t hesitate to reach out. We’re here to help.