Apple Mail delays with Microsoft Exchange email

I had this issue and the fix that worked for me was:

Mail -> settings -> Accounts -> Exchange -> Sever Settings

Then entered the exchange account password again.

Have the same issue. I have multiple email accounts and the update to 15.3.1 was the first culprit, I believe. Tried to solve it with outgoing mail server port changes as the Apple Mail Client is completely hamstrung by trying to work with Exchange. Tried disabling the Exchange account, still did not remedy the failure to send messages. Apple Mail Client created a new "Outbox (on my Mac)" with the draft messages. Opened Draft messages to send, looked like and sounded like they sent...nothing sent! After playing around with the outgoing mail server port, it worked briefly last night, failed this morning! Mail arrives, cannot send. Cannot get Exchange mail via Apple Mail Client and need to resort to Outlook. Outlook sends and receives via the Exchange account without an issue. Apple Mail Client remains in a "Connecting" state. I've removed and rebuilt my other mail accounts, I closed and restarted Apple Mail, I've restarted the MacBook Air M3, everything that is usually the problem solving solution and still met with the same issues for the past few days. DO NOT Delete your Exchange account as you will likely not be able to reconnect it based upon the Microsoft outage reports! So my guess its that the 15.3.1 update has some issues. I am going to revert to 15.2 to see if it resolves my problem because it was working prior to the late afternoon of March 1.

Finally, after a couple of days and discussions with my company's IT dept; I said to myself, I'm not going to wait for things to get fixed on their end, I bought 2024 Microsoft Office for Mac suite; installed it, logged into the systems for Exchange etc. and all seem to be working again. There was some back and forth with Apple; MS Office help is totally bogus (for Mac users IMHO); I don't trust 365 and prefer to have the software reside on my laptop. All is good, fixed, working,.....for now!

I'm experiencing this issue with my personal Outlook mail on my personal phone and on my Macbook Pro (Apple Silicon), and with my corporate exchange server as well on my corporate phone. I can't log into either personal or corporate e-mail using iOS/MacOS services, but I can absolutely get to them through the Web or through the Outlook app.

Clearly something is wrong, but I doubt anyone is going to admit to the issue being on their end.

Similar issue, Apple Mail/Exchange prompted me for the password, I enter it and the spinning gear wheel just keeps spinning. Had to force quit System Settings. Outlook email access is fine through browsers and phone.

The Exchange will prompt you for a new password, then you enter everything and it will not connect to the server and you're back where you started. If you use Outlook on the Mac, I had my email from Exchange work both receive and send. My Webmail for my other accounts will work too. Its a clunky work around but until I try the "downgrade" to Sequoia 15.2 and maybe go to 15.3; I'm staying away from 15.3.1 because between Apples update and Microsoft's "glitch," I think we will be seeing a lot of pointing fingers at each company and no one taking responsibility for their screw up.

The phone iOS seems to work; it's the laptop/desktop versions that are mainly affected. My iOS 18.3 seems to be operating well. I've yet to use it for sending email from Exchange. I'll give it a go! It's the tiny screen that prevents me from picking up the phone and using it as my go to.

That's great. My 15.3.1 Sequoia update for the Apple Mail Client is failing to operate. Apple is aware of an issue, Apple techs spent a lot of time today and last night with looking at everything and settings ad they do not have an answer for the issues.

iOS 18.3.1 is the operating system on the phone and possibly the iPad; they are very different from a MacBook Air/Pro/Mini. My Exchange account seems to work on my phone however, I have no access to my Microsoft 365 and Exchange e-mail accounts today because I wiped the MacBook Air and reinstalled Sequoia 15.3.1. Unfortunately, I thought that when I was reinstalling Sequoia, I would be provided the earlier version(s) and then manually update the Sequoia. However, the reinstall went straight to where I started 15.3.1! Frustrating! Oh well, at least one of my Microsoft accounts seems to work!

I'm having the exact same issue, as well as email that I have attempted to send simply don't.

Webmail is working for me but yes my Apple Mail is a no go on phone and Mac.

I am experiencing the same problem.

Mine started working tonight. I got the enter your pwd prompt and everything downloaded.

Having the same issue

We have the same problem and tried many of the fixes you have outlined except we are running the 18.3.1 os. How do I go backwards?