Close mail App (double click the home button & swipe up)
Open mail App and reproduce the crash
Then...
1. Connect your iPhone and do a sync in iTunes.
2. Open Finder (found in the Dock)
3. Click on the 'Go' menu at the top of your screen, and select 'Go to Folder'
4. Type (or paste): ~/Library/Logs/CrashReporter/MobileDevice/
5. Open the folder with the same 'name' as your device. (i.e. same name that appears in iTunes).
6. Sort by the "date modified column"
7. Find the latest file whose name starts "MobileMail" (hopefully it should have today's date, if it doesn't then let me know if there are any files that do have todays date)
8. Right-click on it, select "copy" ... then paste the copy somewhere else you can easily find it (e.g. your Desktop)
9. Close the MobileDevice window
10. Upload the file to a file sharing site like
ExpireBox or
https://www.wetransfer.com/
11. PM me the upload link (as I assume you won't want to publish it publicly !)
Feel free to take a peek inside the files with a text editor to see if there's any personal information in there you want to purge or obfuscate .... but normally crash files are just that and only contain technical data.