After downloading the latest iphone update, getting the following message: "Cannot Verify Server Identity. The identity of "imap-mail-outlook.com" cannot be verified. Happens everytime I use my phone. Any ideas?

It turns out the problem may not have been my Outlook.com account (which is not related to Office365 in this instance), but rather my Hotmail account.

I deleted my Outlook account with the intent of keeping it off my phone until the issue was fixed, and after a little while the error popup returned. The popup does not reference the account, just the server that is involved, and in this case the Hotmail account was pointed at an Outlook IMap server.

I deleted and reinstalled the Hotmail account, and that appears to have fixed the issue. The settings page for Hotmail now matches the settings page for Outlook; that was not true before.

I have 9 email accounts on my iPhone. I am not sure whether to be proud or ashamed of that fact.

I am having this exact same issue: error popups from outlook.com from the iOS Mail app, using iOS 14.1.

Error is 

"Cannot verify server identity", and "imap-mail.outlook.com" cannot be verified.

My account is installed on my iPhone, and I can actually go into it and check for mail. The account itself is working in the Mail app. But every few minutes I get this popup, no matter what app I'm in.

I have done the following to try to troubleshoot:

• Killed the Mail app by swiping up on it, then restarting the phone. No luck.
• Deleted the account and reinstalled it (after restarting) - twice.

The settings for outlook.com appear to be correct, particularly since I CAN access/send/receive email for Outlook.com.

The popup gives me the option to check Details or Cancel. When I check details, I get told the certificate isn't trusted. I have attached an image of the cert.

I checked in with Microsoft chat support, they told me it was Apple's problem. Of course.

Thanks for your help. 

Solved: Find your problem outlook account and change the incoming mail server host to just outlook.com. The problem is with Office 365. I am sure it will be fixed soon. Basically, you need to create a IMAP account for the workaround using the Apple Mail.

One other thing: Going into the advanced setting for the account, there is no SSL option. There are Sign and "Encrypt by default" options, but when I go into them, the sliders are grayed out.

That is a mail error for your Outlook account. You would need to check the settings on your mail account in the Mail app.

alialqarnia75