IMAP timing out in Apple Mail in Big Sur

I'm having this issue too.

• Upgraded to Big Sur a few days ago
• Can receive all emails via Apple Mail
• Can't send any emails from Apple Mail
• Everything works fine if I go to my mail via GoDaddy's Workspace portal

I've been on the phone with GoDaddy three times today. I'm pretty sure it's not on their side. I've been on Apple chat for the past two hours trying to trouble shoot things. Nothing. I don't have anything fancy installed like Avast or Little Snitch (not sure what that is, but maybe I should look into it.)

Apple doesn't seem to know. They keep wanting to blame it on the provider, but it's not the GoDaddy side if email works 100% through their portal.

AND I can't send emails from my any of the desktops in the house, or iphones.

PLEASE Apple, figure this out and post an answer.

For me I found a workaround.

Any app that uses System Extension which filters network connections seems to be a problem.

But mostly with Apple Mail. Some other clients may work.

https://forum.avast.com/index.php?topic=239798.0

So turn off Little Snitch, Avast anti Virus etc.

I have found this solution from another one (a User had a problem with Sierra):

Its working for the Problem with Smtp Mail and BIG SURE!

I don't know if this solution affects the network security in a way...and it's working only with one type of internet connection. But now i can send my mails again from my macbook like on my iphone and ipad! What do you think about?

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Ok, try these to start with...

Make a New Location, Using network locations in Mac OS X ...

http://support.apple.com/kb/HT2712


System Preferences>Network, top of window>Locations>Edit Locations, little plus icon, give it a name.

System Preferences>Network, click on the little gear at the bottom next to the + & - icons, (unlock lock first if locked), choose Set Service Order.

The interface that connects to the Internet should be dragged to the top of the list.


If using Wifi, instead of joining your Network from the list, click the WiFi icon at the top, and click join other network. Fill in everything as needed.

System Preferences>Network>choose interface>Advanced>Proxies Tab, make sure none are set, like for HTTP & HTTPS.

System Preferences>Network, unlock the lock if need be, highlight the Interface you use to connect to Internet, click on the advanced button, click on the DNS tab, click on the little plus icon, then add these numbers...

8.8.8.8

8.8.4.4

1.1.1.1

9.9.9.9

Apply.

Posted on Nov 5, 2019 12:30 PM

I've been experiencing the same issue and it seems it is bigger than just Apple Mail. Since upgrading to Big Sur I have lost the ability to authenticate to any IMAP server with any email client. So far I've tried with Apple Mail, Spark ancd Thunderbird and all reported some form of connection issues. Curiously, Thunderbird also gave me a warning that my IMAP server was not using SSL when it very clearly is and has been. Like you, I am not having the same issue connecting through other devices connected to the same iCloud account (and therefore using the same email account settings). I'm stuck using my iPhone and webmail (ugh) to check my email until this gets resolved.

Same problem here:

IMAP for different accounts (own servers and gmail) does not work anymore since upgrade to Big Sur. Used to work on Catalina. Nothing has changed, besides upgrading to Big Sur.

Works on iPhone, iPad, Apple Watch, though. But not on my Macbook pro. Tried different things up to a new "install" of an email account. Nothing helps. Very annoying. Can't work anymore.

@syquest - Thanks for confirming that. I use Little Snitch and just updated my license to v5 on Saturday. I had a feeling these two are related but when I tried disabling the network filter through the Little Snitch menu option last night it completely disabled my network connection as if my WiFi went down and I gave up pretty quickly as it was late and I was getting frustrated. Looks like I have a test to do when I get home.

Thanks & cheers.

So to follow-up, I can confirm that the issue is 100% related to applications with a network filter.

As mentioned above, I am running Little Snitch (v 5.0.2). Attempting to disable the network filter using the menu option killed my networking until I restarted; no amount of attempting to turn it back on again restored my network connections.

After rebooting and confirming that networking was re-enabled, I completely uninstalled Little Snitch (the instructions in their help docs have not been updated for 5.0.2 - deleting requires dragging the Little Snitch app bundle to the trash and confirming the removal of the network filter extension from the pop-up dialog) and rebooted. Immediately after rebooting, I opened up Apple Mail and it worked again and started downloading the backlog of email for the past two-plus days.

I'm currently submitting a bug report with Objective Development, the makers of Little Snitch, although as mentioned above it appears this affects any application with a network filtering extension in Big Sur.

fyi, Prior to Big Sur update I was using two different SSL check apps and had been using same for several years. After update, neither worked and I trashed both as a consequence. It is curious ... only haven't had time to consider all the changes ...

I had the same problem on two Macs. I found that by deleting all network filters (Avast, Little Snitch) in the Network system preference, the problem immediately evaporated. Am still experimenting with various combinations of these because some seem to work on their own but not together...

There is definitely a lot more problems to Apple Mail.

I also cannot get my Google SMTP to work. Used to work for years before the update....

Turning off Little Snitch is also not a solution. APPLE APPLE what is wrong?

Not directly related to BigSur, same problems arised some days ago with all imap accounts (in particular gmail) with Catalina too. Somehow, this timeout / data quote full problem has been solved up to today, although downloading from imap server now slower.

I heard back from the makers of Little Snitch and together we figured out that Little Snitch and Avast do not play nicely together in Big Sur. I was able to restore my IMAP connections in all applications by completely uninstalling Avast and replacing it with Sophos (at least for the time being) since disabling the "Email Shield" in Avast had no effect. With this change made I can still use Little Snitch, have decent free AV and connect to all my SSL-enabled IMAP accounts.

I am having same issues on my MBP which I upgraded to Big Sur a few days ago. I am running the new version of Little Snitch on this machine, having upgraded from the older version.

I purchased a new Mac Mini M1 two days ago and I've installed the new version of Little Snitch and AVG Anti Virus and the email app is working perfectly.

I have to wonder because it was a clean install on the Mini there isn't any "stuff" left over from the old version of Little Snitch. The alternate could be that Big Sur works better on the M1 chip.

At this point I'm not prepared to do a clean install on my MBP - will wait to see the the subject matter experts say.