I thought I would share issues I recently encountered in setting up Outlook.
Recently I had to migrate my Google Calendar to an alternative calendar while keeping my Gmail account. The reason for this is complex, suffice it to say my Gmail account is actually an alumni benefit from my Alma mater.
Many years ago I used my Yahoo.com email address create an account to log on to Microsoft Live. This has never been an issue since I have always been able to sync to OneDrive and Microsoft 365 using this login. It has worked on my PCs as well as my Android phone.
Due to the issues with Google Calendar, I decided to go ahead and use Outlook.com for my Calendar. I was able to login to Outlook.com using my Yahoo.com email. However, when I wanted to log on to the Android Outlook app it would not accept my Yahoo.com Microsoft Live login. This was perplexing since I was able to login to Microsoft 365 and OneDrive on Android. I would select the Yahoo login and the set up on the Outlook app would reject it. Side note, I also tried to set up Outlook on the desktop and I ran into various errors using the Yahoo email.
After some research I realized my Yahoo.com email was an alias. (This was never obvious since I never used outlook.com.) My resolution was to create an alias using a new outlook.com address while logging into my Microsoft account. This email does not have its own email account but it points to my original Microsoft account (and its underlying email address). Once I had this new alias, I was able to log on to my MS account on the Android Outlook app.
Additionally, using the outlook.com alias resolved the desktop Outlook issues. The added benefit is I can use the outlook.com address to send emails to the account for scheduling. It also allows me to sync the desktop, outlook on the web, and Outlook on Android.
