I have a preference in a profile that points to a directory that doesn't exist. It's from an account that no longer exists. Arguably the preference shouldn't exist, but it does, and that shouldn't break the import process.

Importing this account throw NS_ERROR_FILE_TARGET_DOES_NOT_EXIST while trying to copy the mail from this account. Nothing catches the exception and the import just stops, with no feedback to the user.

Depends on D121576

Pushed by geoff@darktrojan.net:
https://hg.mozilla.org/comm-central/rev/c7bc57790347
When importing mail, don't try to import a directory that doesn't exist. r=rnons