Mail wont take gmail online

Back up all data. Delete the account in the Internet Accounts preference pane, then add it back. Test.

If that doesn't work, try port 993.

http://email.about.com/od/accessinggmail/f/Gmail_IMAP_Settings.htm

You are welcome.

How does one "back up all data" before removing the account? I assume that all of my local folders, filled with important emails, will be deleted if I remove the account? Is there an easy way to back up this data specifically and reinstall it after adding the account back in?

So frustrating now... I have constant iMap issues with gmail.

Time Machine Versus Clones and Archives

Commonly Used Backup Methods

Time Machine Basics

Time Machine Basics (2)

Ah, yes. Backing up automatically with Time Machine in general, I can do. And I can - and have - recovered specific files that way. Files that I know the name and/or location. What I'm not aware of, is a way to restore only my local email folders.

I have manually exported every folder - but that takes a significant amount of time as I have hundreds that are nested. The chance of missing some is huge. I'm looking for a way to back up every one of the folders... or to find them in my Time Machine backup somewhere?

Linc, your solution did not work for me. I deleted the account in Internet Preferences. Let Mail go through the process of setting back up the entire account, deleting old emails, then re-adding them. All for it to give me the same exact error message. Total waste of time. Any other ideas? (and yes I'm already using port 993).

You might want to consider starting a new discussion. Since this one is marked solved, less people are likely to look at it. You can link to this one.