Configuring preferences and options in Outlook.com
Hello newfox
Hi, I'm Karl and will be happy to help you today.
The fact that you see an Outlook_longuglycode email address means that the <Primary Alias> email address for the account is a non-Microsoft email address.
This issue is explained in
Outlook.com email account appears as "outlook_[long series of letters and numbers]@outlook.com" in Outlook for Windows
https://support.microsoft.com/en-us/office/outl...
Summary solution
#1 - Create a <NEW> Outlook.com alias email address for the account
Add or remove an email alias in Outlook.com
https://support.office.com/en-us/article/add-or...
#2 - Make the new alias the <Primary Alias> as described in the above article
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I looked up how I could change that and everything talks about aliases. But that’s about adding a new way to sign in using an email you already have.
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Just to clarify something, while you can use different alias addresses to sign into the same account it also allows you to send emails from any of the alias addresses. It is definitely not just about signing into the account.