NEW Outlook app: how to add an IMAP account with user name different from email address?

This is really really annoying. All my family email addresses have different IMAP login user names from their actual email addresses - just how the hosting provider sets them up and now we cannot use Outlook as there is now way to actually add these types of accounts. How can Microsoft miss something as obvious as providing a user name box??

Is there any indication when this might be fixed?

Same here, almost a year later. And today they disabled the old Outlook, I can't switch to it anymore, just the new one. Still not fixed. This is the worst piece of garbage from MS since I remember. Switching to another email client.

I had the same issue. I was able to get round the issue of a different logon id to the email address by setting the account up in control panel -> mail settings and adding the account there where it allowed a different user name

I also had another issue - the set up now insists on sending a test mail successfully. Unfortunately the mail sever I was using requires a mail pick up before sending. Of course setup doesn't do this. I got round this issue by ensuring I was logged on via webmail first and then doing the mail set up.

Are we near a fix for this yet? I would like to have outlook on my computer again

I've got both old and "new" (dumb) Outlook installed and can only use control panel to set up old outlook accounts. Did you face this?

I only ever use old outlook, haven’t tried new outlook but it sounds like a backward step