Apple Mail on iOS15 / Outlook.com MFA Application pwd

I have the same issue. I upgraded to an iphone 13, installed IOS 15 and then 15.1 on the phone. Email was working fine on the older XR running IOS 14. But now, with two Microsoft accounts - one is O365, one is Outlook, I can get into neither. I keep getting asked to sign in on both, and when I do, the reply from Microsoft is the password is incorrect. I have to believe that Apple is 1) not sending the correct password to Microsoft (because this password works on other devices) and 2) if you look in IOS under passwords, nothing is being stored there. This is very puzzling, so I suspect something is wrong with the password facilities in IOS 15. I do not believe this is a Microsoft problem, as others have suggested. There is a bug in IOS 15.1. Shame on me for installing it. I rely on this working through the day, so Apple needs to address this.

I'm having the same problem with iOS15 on iPad and iPhone. Once a day asks for password to Exchange Server account. Never did this before. I just changed the account to be the default so I'll see if that helps. I've deleted the account on both devices. That did not work. I'm assuming this is a problem with iOS15. We'll see if Apple cares enough to fix it.

I'm experiencing the same issue. I spent 45 min on the phone with Apple support and worked with three different reps. they all said no one has reported this issue before. Glad to know I'm not alone!

I have worked extensively with our IT dept and they have yet to find anything on our Exchange server that would cause this.

Mine goes 1-3 days between prompting for the password. I have tried multiple times with wiping the phone and starting over. I then added mail accounts in different orders each time and no matter what, as soon as I log into my iCloud account, the phone prompts me for my Exchange password.

iPhone 13 Pro Max with iOS 15.0.1

I have exactly the same issue!

My company uses Exchange 2013, no changes made to the Exchange server and since upgrading to iOS 15 email app at least once a day is asking for a password. This does not appear to cause any issues for any non Apple Users or those with older iOS versions.

The problem is, my domain account is highly privileged meaning when the wrong password is provided 3 times, the account is locked out until manually unlocked. When my account has got locked out for 2 days in the row, a security investigation was launched in to reason why the account was locked out yet again and whether the company is being attacked. This has taken up business time and resource to look in to an issue caused by an iOS Update, totally unacceptable

This is causing my account to be locked out EVERY SINGLE DAY stopping me from being able to work!!!

This seems to be a problem only on Apple’s native Mail app and Exchange email account. I also have Outlook mail app on same phone 12 pro and it doesn’t prompt for password every 24 hours but the Apple Native Mail app does.

I checked mine and the time zone was correct (Eastern). But I clicked on the link anyway and it showed me a map where my calendar was set to Pacific. I clicked on Washington DC on the map and was able to change my calendar's time zone to match my email time zone.

I just did this so I don't know if it works or not. But I wanted to follow-up to this post and tell people to click on the time zone even if it's correct since the calendar may not be. Let's hope this works!

Been having the same issue ever since updating to iOS 15. I have 3 mail accounts on my iPhone SE. 1 Office 365 Exchange with MFA enabled, 1 Zoho account with MFA enabled and 1 Zoho account with no MFA. The only account having the issue is the Zoho account with MFA enabled. I have the re-enter the app passcode about once every 2 days. Ironically, the Office 365 account is fine unlike most people here. Even though MFA is enabled on the Office 365 account I don't have to use an app passcode because the iPhone can integrate with the "modern authentication" Microsoft uses. With Zoho I have to use a generated app passcode and that's the one with the issue. Oh and I have all 3 of these accounts on Outlook on my Windows 10 desktop, no issue there.

Sorry, no answers here, just wanted to provide another data point.

I have been experiencing this same issue since I've upgraded my devices to IOS15. The issue continues to happen for my work email on an Exchange server. The issue is happening on both my iPhone 11Pro and my iPad. Deleting the email account and re-setting it up has not solved the issue on either device. It is frustrating.

That's incorrect. We're on-premise exchange and I'm one of the exchange Admins. There's been no patches applied. No new security policies or anything changed in months. Test devices on ios 14.x aren't having the problem. ios 15 is the problem.

The problem with using 3rd party mail apps (I've switched to Outlook to deal with this issue, too) is even if you move all your accounts over you still don't have integration with the native iOS calendaring and Contacts features. To me this is a huge step backward.

I checked that, mine has been set to “off” the whole time this has been going on.

I just tried changing the number of days to sync mail and rebooted. We’ll see if that makes a difference.

does @Apple read ANY of these posts?!?!

This is a huge problem. I cannot use Mail, Contacts, Notes, Calendars, or Reminders on the iphone. It keeps prompting for hotmail password every so often that it is annoying. When I used Outlook on the phone instead of native Apple apps, there is no problem. APPLE'S RESPONSE -- CONTACT MICROSOFT! This is arrogance at its worst!!! This is an Apple Bug and needs to be fixed!!!!

I should elaborate that it does this for every Microsoft account that is personal. It does not do it for my college or work accounts which are Microsoft 365.

I am having the same issue with only my work mail which is an exchange. I've deleted the account and re-added it. It continues to ask for my password every day.

Yeah I am one of the exchange admins. We haven’t changed a **** thing. iOS 15 is the cause.