IMAP, allow insecure authentication

Hello !

Using Mac OS high Sierra 10.13.3 see this article Automatically manage connection settings in Mail on your Mac - Apple Support

The settings are dimmed and you don't need to add manually , the server settings will get automatically managed by its own , this is a change in newer version of Mac OS high Sierra , even the Mac user try to set it won't .

Hello and welcome to Apple Support Communities, mauzzz.
If I understand your post correctly, you're having trouble saving your settings for your mail account. I'd like to help.
Safe mode will tell us if the issue is related to a startup item or plugins, and sometimes corrects the issue. This article will tell you how: Use safe mode to isolate issues with your Mac
If everything is working correctly in safe mode, but is not working when you get back to your user account, please check the section titled "If an issue doesn't happen in safe mode" for the next troubleshooting steps.
If the issue continues while in safe mode, a test user will let us know if the issue is isolated to your account, or system wide: How to test an issue in another user account on your Mac. If the issue happens in the test user also, then please check the section titled "If an issue happens in more than one user account."
Let us know if that resolves this issue for you.
Thanks for using the Apple Support Communities. Take care.

You can follow the guidance of dianeoforegon the best method if any issue are in the mail delete the account and add it Set up Mail with email accounts - Apple Support

Use SSL to connect to an SMTP email server - Apple Support

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I have exactly the same issue. It's a bug. It also present in the betas of High Sierra. I cannot use my main work email account without that option checked, so I am using an alternative email client for the time being. I am just waiting for 10.13.1. Hopefully, it will be fixed there.

If it's a Gmail account you might need to set to allow insecure apps in Google Settings.

Allowing less secure apps to access your account - Google Account Help

Found these comments by a user in my notes:

Called Apple Support.

When I called (chatted, really), they had me open KeyChain Access and search for "veri"

I went through each entry and deleted all the ones with a red warning (usually including "unauthorized" or "Unknown").

Then they had me restart and Google accounts started working again, and I could add new ones.

I did have to re-enter all the passwords, but it's not a bad as I feared it would be.

mauzzz wrote:

I can't imagine this effects only a few users. Did you send feedback?

The person you are asking if they sent feedback is using a beta version of software. They nor we can discuss beta software here. If you are using beta software please read the NDA you agreed to and report the issue to the beta group.

If you are not using beta software your issue is specific to you and your system configuration. It does not affect others as it is not a systemic problem. Tell us more specifics about your Mail configuration.

Just a thought... check with your provider to see if they offer secure settings. I often see two sets of options to connect. You want to use secure settings if at all possible. If they don't offer secure settings, I would look for a different provider.

The article deals with accounts that use SSL/TSL (and security certificates). The issue mauzz mentioned is about accounts that use insecure IMAP authentications, no certificates involved. So the article does not apply to this issue.

It's not a settings/setup issue. It is a bug.

It does affect others. As I said, it is my work account that requires this setting to be checked. Everyone in my workplace that is using Mail.app in 10.13 is having the same problem with their work email. It is a national research institute with hundreds of informatics researchers. My boss downgraded back to Sierra because of this specific bug. It is a systemic problem in Mail.app in 10.13. It is not a configuration issue. It's ok, all software has bugs, including Apple's. But refusing to acknowledge it and blaming mauzz's configuration hinders the fixing of the bug and the improvement of the quality of Mail.app

Most commercial/consumer providers offer secure settings. As I said, it is my work email. It is a large national informatics research institute. Just because they use "insecure authentication" doesn't mean that it is insecure. They use much stricter ways, to ensure the security (SSH key-based machine authentication and SSH tunneling).

Yes ! That is same case I use . I use Davmail to transfer my mail from exchange server to my Mac . But mail.app IMAP setting does not allow the insecure connection to my localhost. By the way, SMTP setting accept the insecure connection. This is big BUG but not be repaired even in the beta 4.

I feedback this to Apple support in China. After about an hour chat, they confirmed the bug in their Mac but have no solution.

Sorry for my poor English.

Just to be clear, this is a peer to peer support forum. While on occasion, an Apple tech will reply here most replies are from users just like you.

I was assuming you were a single user not from a large group like your institute. Normally, you do not install the newest version of an OS to your users since the first release is generally buggy. Someone should have installed High Sierra to test before having others upgrade.

I have two suggestions until Apple fixes.

1) Use webmail. Since it's IMAP all changes will be reflected when you download.

2) Use Outlook, Spark, Thunderbird, Postbox(has 30 day trial) or other third party app to see if they will connect.

Single user or a large group is irrelevant, Anyway, as we are an informatics institute, lots of us need to use the latest Xcode tools and compilers. So we cannot wait because of a bug in Mail.app. We are not a company where the main function of a computer is Microsoft Office.

And as I mentioned before, I am using for now an alternate email client (and yes, I can connect fine).

But I am used to and my workflow is centered around Mail.app, so it is quite annoying.

Let's hope the bug will be fixed in 10.13.1