Roderunner has a nice document that should help, and the link works for me to open a Word (docx) document.
You need MS Word or a program that can read a docx file to use the document in the link.
If that Word doc doesn't get you sorted, a few things I'll add:
I use IMAP Gmail with WLM 2012 and it works very well for me - i never saw your "800cccd2" error.
You may need to log in to the Gmail web page to enable IMAP and/or POP for your account.
That's shown in Roderunner's doc (and my screen print below).
You can also do a search for 800cccd2
and try other suggested solutions you find. Re "How do I change it to POP3?"
When I want to change an account type from IMAP to POP3 (or any account type change),
I create and test a new client account for the same email address with the new (POP3) account type.
Then I delete the old (IMAP) client account that i don't want to use anymore.
I don't know if there is a way to change an account from one type to another after the account is created.
In my screen print below, i can NOT edit/change the server (account type) from IMAP to POP!
I haven't found if this type of change is possible without creating and deleting an account. I DO NOT ever create or delete a new email provider (GMAIL) account to make this type of change!
If anyone knows an easier way to change an account from IMAP to POP, I'd like to know how to do it.
note: As far as I know adding an IMAP account creates a specific data file/folder set when the account is added to an email client (WLM).
Here's a WLM screen print - i can't change the server type fom IMAP to POP...
Here's a Gmail web settings page that shows IMAP and POP settings: