Please note that our Microsoft Q&A forum is a public platform, and we will modify your response/ question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.
Hi Mack McKinney,
Welcome to Microsoft Q&A.
In Outlook for iPhone, this usually happens because the app is in All Accounts (Unified Inbox) or is still defaulting to the older mailbox for sending.
Try this quick fix:
- Open Outlook and tap the Inbox/Menu icon (top-left).
- On the far-left vertical strip, you’ll see two account circles (one for @SolidThinking.org, one for Mack@…).
- Tap the Mack@… circle. This exits All Accounts and makes Outlook behave as if the old account isn’t active without deleting it.
If you still see the old address when composing a message, start a new email, tap the From field, and switch it to Mack@… (and set it as default if that option appears).
If you let me know whether the issue was the wrong inbox being shown or the wrong From address when composing, I can point you to the exact setting to lock it in.
Please let me know if this proves useful to you, or if you would like further assistance.
I'm looking forward to your reply.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment”.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.