After months of getting stuffed around with this problem, trying other apps, researching why it's happening, etc, I've made some discoveries I wanted to share. This is part of a deliberate attempt by Microsoft to push people off the EWS connections, because they announced years ago that it will be deprecated, but most 3rd party services like Aquamail haven't yet moved to using the Graph API. This problem will affect almost all Android apps (except outlook of course).
If you remove your account and re-add it to try and fix it, email will work again, but you will lose your contacts (which is a huge problem if you don't store your contacts on the phone or SIM card, and rely on your synced contacts to know who's calling/texting)! If you did remove your account and re-added it, and have now lost all your contacts for your phone, here's a 'quick fix' to manually copy them to your phone (not synced, it'll be a separate copy) - I know this is a lot of steps, but they're actually very simple to follow (just a bit wordy, to be as clear as possible):
- On a computer (this doesn't work on mobile), open outlook.com in a web browser and go to the contacts (named 'People', the icon is of 2 people, not 3), then click on All Contacts on the left side
- Select them all using the checkbox at the top of the column and click on 'Manage contacts' in the top bar and select export – save the file somewhere on your computer you can easily find it again
- If you're on Windows:
- Click the search icon in the taskbar and type in contacts – the result is a folder, not an app (you can also use Explorer to go to C:\Users\<your username>\Contacts)
- Click the Import button in the top bar and browse to your csv file – you may be prompted about duplicates, just say no to all
- Now click the Export button and save to vCard (VCF) – this will create a file for each contact, so the more contacts you have, the more painful it will be to put them on your phone
- If you don't use Windows, you may need to use a 3rd party app to do that conversion
- Next you have to get these onto your phone – you can email them, use cloud file storage like OneDrive or Dropbox, or use any other method you're familiar with
- Finally, open your phone app, go to the contacts tab and then go to the settings (tap the dots or hamburger menu in the top corner) and then tap on import/export contacts
- Select to import from storage (this may vary slightly) and then select where you want them to go – probably your phone, unless you've already setup a new account that can do syncing
- Browse to wherever you saved all the VCF files and select them all (tap and hold on one, then you can tap on all the others)
- Verify that your phone now has those extra contacts added – if you open your messages app, you should see the list of messages change from numbers to names
Note that this doesn't address calendar syncing or getting your contacts back into Aquamail, but you can use this as an opportunity to clean up the contacts that don't have phone numbers, since they'll only be used for calls/text. It may be possible to import these contact vCards into Aquamail too. Maybe one day if/when Aquamail starts using Graph for the connection to Microsoft, we can go back to having synced contacts again, but this is better than nothing for now.
