There was some discussion about this problem with those of us clinging grimly to High Sierra. I found this fix online - it may even work on other OS's. I have followed the instructions and am now waiting to see if it works. Here is the link: https://appletoolbox.com/mail-keeps-crashing-on-macos-high-sierra-fix/#Fixes_For_When_Mail_Keeps_Crashing_on_macOS_High_Sierra
Looking on line Drew, it seems that this problem is not aimed just at you! Something has been changed by Apple causing Mail to misbehave and plenty of pepople are really cross about it - but there has been no solution that I could find.
I guess you will have to wait for Apple to cure th problem.
I am having the same problem - frequent crashes whilst preparing a message. Fortunately the message is saved. Am using High Sierra. When a pop-up appears saying, "Mail quit unexpectedly" and I click the option to Report, the pop-up vanishes and I don't see how I can give Apple feedback.
Out of interest, did this happen when High Sierra or Mojave was the current OS? I assume not as you're only now mentioning it. (High Sierra was released in September 2017 - have you had issues ever since you upgraded to it?)
Have been on High Sierra from soon after it was released. Had occasional crashing since then but not enough to cause concern. Seems to be more frequent Mail crashing during the past month. Can accept it in view of low Mail usage and the fact that crashed messages are automatically saved.
I switched to using Mail when I changed ISPs last October. Crashes were not a problem initially, but have grown in frequency recently. Looking online this problem has occurred in the past - but the fix that I found (see link above) was posted recently. Shame it didn't work. There was another suggestion to use if Mail wouldn't open, but that hasn't worked at all! If someone can show me how to set up my iCloud address in old-fashioned Entourage, that would be worth trying!
Due to the crashes, I am starting to consider an alternative app to Mail. 'Spark" seems to be one option so I would be interested in any comments on this or other options.
As it's a recent thing for both of you, have you had any updates to Mail recently or any to the OS itself? Something must have changed somewhere to make it start crashing as it used to be OK. (It's a while since I use High Sierra but I don't remember Mail ever crashing but then I moved to Mojave when it launched.)
Got nowhere with Apple SUpport. They don't offer support for old geysers - sorry old Macs, and my iMac definitely belongs to that category. I was advised that Mail will work perfectly if I update to Catalina - the only way I can get my iMac that high is with a ladder. However, as Mail was also playing up on my MacBook Pro running El Capitan, I am updating to that and hoping it won't torpedo any of the apps I use. Mind you, I'd love to see Appleworks running in 64-bit mode.
Very impressed with the functions shown in Thunderbird's latest version. However in trying to set up my existing email accounts I fell at the first hurdle as I am not sure what the password might be for my iCloud address. I have tried my Apple id password and it has been rejected. I have an uncomfortable feeling that I won't get by with the other two accounts either...
The password for iCloud email is your Apple ID password. Try logging in to iCloud.com in a browser (delete any password offered by the browser and type in manually) to prove you're using the correct Apple ID password.
If you have two-factor authentication enabled on your Apple ID then the password when using a third-party email client (such as Thunderbird) for iCloud email is not your Apple ID password.
In this case you must instead generate an application-specific password for use in your email client from your Apple ID account page.
Andrew - I don't have an issue so haven't investigated thoroughly but whilst I appreciated you can generate an application specific password, I don't read that page that you have to. I read it as a method of maintaining extra security rather than compulsory. But in light of Michael's experience, perhaps it is (assuming he's got his Apple ID password correct (sorry Michael 😉))