Mailspring on a Mac (High Sierra, Big Sur): Reply to a message and begin typing, editor hangs after about a sentence


Recently installed Mailspring 1.10.1 on both my macs at home. Overall it works really well. However, when I receive an email and try to reply to the message, the editor often hangs mid-sentence as if the app has frozen. I am unable to click on anything within Mailspring to free it up. However, I can switch to other apps on the Mac and check things (like the Activity Monitor, etc). Nothing seems out of the ordinary. The CPU isn’t pegged, there is plenty of memory available.

After a few moments, the app reports: Not responding, do you want to “wait” or “close” – I choose “wait” and then the control is returned in the App and I can continue typing.

I did notice that the helpers (glowing pink ball that directs you to one of the features of the app) seem to be connected to the freezing but I can’t determine if this is the case. I’ve already sent a lot of emails so those helpers shouldn’t be showing up at this stage.

To Reproduce…

  1. Open Mailspring
  2. Open an email
  3. Reply to the message
  4. Begin typing a sentence or two… observe the freezing app

Steps to reproduce the behavior:
I have configured:

  1. A custom HTML signature for the account
  2. A mail alias in the Google account that is set as the default “from” address

Expected Behavior

I would expect that the mail editor won’t freeze for the entire duration as I’m typing an email.


I can supply screenshots if it is useful, but it will be hard to “show” the app is frozen. Probably I’ll try to add a screencast.


  • Mac OS High Sierra (10.13), Mailspring 1.10.1
  • Mac OS Big Sur (11.5.2), Mailspring 1.10.1
  • Installed with the Zip file (both cases) and dragged the app from the downloads into the Applications folder

Additional Context

When using the Monterey iMac at work, the mail editor never freezes. Just on my older machines at home.

Here is an example screenshot of what happens when the editor hangs. I just started typing a new email to this person and the editor froze after a few seconds of typing.

Then the error notification popped up.

Once I click “Keep waiting” then control is returned and I can keep typing.

One more thing I discovered: it might be possible that the spelling check is causing the editor to freeze. I’m going to try disabling spelling on both the Mac keyboard setting and the Mailspring setting to see if that makes any difference. I have a feeling on older Macs it might cause things to slow down… get stuck…

NOTE: Since I disabled spell checking a few days ago, the editor has not frozen at all. It seems that the automatic spell-checking on older Macs isn’t functioning smoothly. Perhaps there are some internal permissions I need to configure in order to allow it to work smoothly. For now, I’ll keep spell-checking off.

Hi - I see this too on my power Mac running Big Sur 11.6.3 - it’s a 2.6GHz quad core i7 model. Basically the editor gradually slows down if like me you type fast. I think it might have to do with the interface to the OLED display strip at the top of the keyboard. I have noticed that as I type the words I am typing continuously update the display inn real time. This is presumably so that I can run spell checking or some such feature, but I think that keeping the display updated is too much for the machine and this ‘feature’ is causing the editor to become sluggish. Is this possible? I don’t mind looking in to it when I have time if that would be helpful. Thanks for reporting this bug - I was about to report this one myself, but it seems that they might be the same issue.

Actually, when I follow your lead and turn off spell checking, the sluggishness goes away even thought the OLED screen is still updating, so I was wrong and you were right - it’s to do with the spell checker. All the same, turning the spell checker off is a blunt instrument - many of us have lousy spelling! I suggest that this issue becomes a bug - Mac spell check feature breaks the Mailspring message editor. As I said, I can try and fix it at some point!

Pretty interesting. I have not had any problems so far on my Mac 12.3 Monterey. I will try to reproduce it, but I am not sure if that is easily possible. So far the spellcheck works as intended.

Thank you @eddaw1 and @Phylu for your responses. On my Monterey iMac at work, I’m not seeing the issue. Just on my older Mac at home running High Sierra and my MacBook Air running Big Sur.

Perhaps spell checking on older Macs has a different interface than in Monterey. I noticed in the newer OS, it seems to ask permission for every app I use to do every little thing.

@tallthom I will need to see if I can get an older MacOS version running to replicate the issue. I can totally imagine that the electron native spellchecking (which we are using) has some problems with older mac version. Maybe the next electron update may help as well. If you want, you can try a custom built from the master branch that includes the latest electron version.

I just tested this out on a fresh install of MacOS 10.13 High Sierra on a 2010 Mac Mini. Sometimes the typing becomes a bit sluggish but I have no freezes.

Also the sluggishness does not seem to be related with spellchecking as it is the same whether I have spellchecking switched on or off.