Outlook Android App error occurred during authentication. Please try again later.

I was helping a friend of mine who had this issue, and I was able to solve it for him.

However I don't know exactly what he did to get to this state. We tried all the steps outlined in this thread except the factory reset. Nothing worked but I decided to sign out of all microsoft accounts I could find on the tablet. I found Onedrive was signed in. I tapped sign out and it took me to the android settings accounts menu. I removed that account. I also noticed a "Samsung" account using the same outlook email. I tried to remove that account too but it asked for the password. When my friend entered the password, it was a different one. My guess is that this account was causing some authentication mixup when Outlook tried to authenticate using the same email.

Steps:

open android settings

go-> Accounts and backup

go-> Manage accounts

Sign out of Samsung account (with same email)

Sign out of any other microsoft account

Also follow steps to remove cache and data from outlook, uninstall

Reinstall Outlook and try again. Now it asked for password and we were able to sign in. Note: we selected Office365 account, Outlook account did not work. These options were not presented to us until we deleted those accounts.

TL;DR - somehow adding three accounts at once (one outlook, and two office365) finally got my main account up and working on my mobile

I think I may have found a way round this. I have exactly the same problem, tried exactly the same solutions, including a different office365 account. Came across this thread, got depressed, and realised I would have to return my new phone to Amazon. Within that process I did telephone Samsung, and they tried really hard, but still failed. So I have requested a return (which won't now happen 'til after the weekend).

BUT, I am an inveterate fiddler, and I tried the new account button, and created a new ?@outlook.com account at that worked. So having broken past the opening screen, I then tried adding my main Office365 account, and (as might be expected) failed.

However, in going into look at the new account on my desktop, it presented me with a QR code to download mobile outlook to my phone. So I thought it was worth a go. So I uninstalled the old one (again) and loaded a new Outlook App via the QR code. Which offered me three pre-existing accounts I could add (the new outlook, my main Office365, and another office 365 that I had been trying in case it was my main account that was the problem).

Selecting my main account, and deselecting the other two gave me the same error message and returned me to the initial screen. But on a whim, I tried again, and kept all 3 accounts selected. I got the error message again, but just for one of the accounts - the outlook.com account got through (as I might expect) but so did my main Office365 account!!!

Frankly, while the account seems to be fine, the process of getting there seems a bit of a fluke and potentially fragile. So I tried it again, and it worked again (although, I have no idea why the other 365 account is being rejected). So I now need to see if I can cancel my return.

Sorry, bit long winded, but I figured if anyone is going to take the risk in following my footsteps, a fuller explanation might help (both confidence and repeatability). It may also help if anyone at Microsoft (or Samsung) is seriously looking for clues and insights into what is actually going wrong for the rest of us??? Hope it helps.

Judging by the 3 pages of frustrated replies and absolute disregard shown by Microsoft, it sounds to me that the best solution would be to use any other mail app instead.

Simple fix, use a less broken mail app.

Please keep in touch, I am in the same boat and want this resolved. I have tried other support options and get the canned responses. Thank you.

I am a different user and having the same issues. It's still not fixed and my IT person was trying to help me also. I use my Outlook on my 1 year old Android constantly and need it to work.