I have an email account that supports IMAP, and I also have a gmail account. I want to import a folder from the email account that supports IMAP to gmail (my SENT messages folder). http://lifehacker.com/332624/import-messages-into-gmail-via-imap suggests a solution for that. Basically, you take a mail client, set up IMAP for both gmail and the account, and then drag the folder into the gmail account. This sounds okay, but the thing is that I want the SENT folder to be synchronized with the gmail account. I don't mind every once in a while dragging the SENT folder to gmail folder manually, but my question is - will it create duplicates from the SENT folder in the gmail account?