Removing old mails after switching mail client I am very new to Mac. I was previously using Apple Mail. It downloaded all my mails to a local directory (> 1 GB). Now I have switched to Spark and added two of my major mail accounts in Spark. before doing this I removed (unchecked only Mail option) those two accounts from Apple Mail client. What I am worrying is as I am not using the previous mail client the previously downloaded mails should not eat up my storage. But I still see there are mails downloaded in my storage.

neel@air$ du -hs /Users/neel/Library/Mail/V4/*
 28K    /Users/neel/Library/Mail/V4/7E9DC725-1141-4372-9558-9387681B6536
133M    /Users/neel/Library/Mail/V4/9061FA6F-8C9A-46AE-A697-00E71973CE4E
120K    /Users/neel/Library/Mail/V4/BDE6ECBE-0F31-40ED-8E12-1783CEE41C93
1.0G    /Users/neel/Library/Mail/V4/C34B3F07-E470-4CAB-A741-A6BD1E3D4F19
 28M    /Users/neel/Library/Mail/V4/MailData


Now are they mails previously downloaded by Apple Mail client or they belongs to spark ? If they belong to the previous client how should I remove it ? is it safe to just delete them all ?
Basically, Apple Mail and all other mail programs download caches from your email account. these cache files often work as a backup. removal of accounts doesn't remove them. And that is a good news for you. If someday you lose your emails from the server, you are assured a copy of the emails sits on your system and you can recover all your emails from there.

thanks,
Jason