emailgmailimapmail.app
I am using Mail.app to access my gmail account (business / google apps email).
I want to delete a big pile of emails in Mail to clean up my inbox, but I want to keep those emails in gmail (IMAP server) so I look them up in the future by logging directly into gmail.
I'm new to Mail. Is there a setting where I can delete my emails in this account freely in Mail without deleting them at all from the gmail?
You will want to make a new mailbox with storage only on the Mac or use the Archive function in Mail to archive an entire folder/mailbox.
The built in help will guide you through the Archive path.
I just make folders "On My Mac" with the year, and then make Q1, Q2, Q3, Q4 folders inside to keep each relatively small - you might only need one folder per year or one folder.
Once you move the message and are comfortable that it's on your mac with attachments intact, delete the original message from IMAP and your quotas will be happier.
Debugging Mail.app on OS X is fairly easy - especially in the case you describe where the problem is with one account.
Open terminal and type this all as one long line (it's split here for readability):
/Applications/Mail.app/Contents/MacOS/Mail -LogActivityOnHost imap.gmail.com -LogIMAPErrors YES >& ~/Desktop/MailConnection.log &
The harder part becomes making sense of the volume of data being logged, but again it seems you have a good handle on the scope of the issue. I would take a gander at your IMAP and label settings in gmail preferences to be sure your account isn't suppressing those folders for IMAP delivery.
Best Answer
You can check
Mailbox Behaviorsin your Gmail account setting (underAccounts) and checkStore deleted messages on the server. This will make your messages still available in other clients even if you delete them in the Mac where you have this setting.Reference: Mail (El Capitan): Mailbox Behaviors preferences