Which of our tools is giving you problems?

The mail extension.

Attach a screenshot of the version info for all installed components (how to: https://gpgtools.tenderapp.com/kb/faq/where-can-i-find-version-info...):

You can check the screenshot

Describe your problem. Add as much detail as possible.

Mail app took solid 30" to open every time I have to open it.

What did you expect instead

Open instantly as always

Describe steps leading to the problem.

Just open mail

Are you using any other Mail.app plugins?

No

Notes

Hey!

I just fixed the issue, but I thought it would be helpful for others that perhaps are experiencing the same issue.

The problem was that mail was taking 30" to open, when before it opened almost instantly. Not a great deal of a problem, but annoying.

As you can see in this thread in macrumors, I solves this issue before just deleting the contents of ~/Library/Containers/com.apple.mail/ but after updating to Big Sur, this stopped working.

However, I just solved the issue changing the default key on the settings of the app (on the System Preferences panel). And the fix persisted, even after changing back to the original key…

I hope this helps any one with this same issue.