Email forwarding from Gmail to Hotmail

So when I had created the account I had transferred my gmail emails to my new hotmail account.
Then there was a gap of few months in the middle where no emails got transferred.

Now If i again import emails I will get all my old emails of gmail again along with my new emails.

Any way to no duplicate emails getting imported and only import certain months?

This could probably be done with the IMAP Tools as long as they are able to figure out the duplicates. @rfs9999 might have more to say about which tool is the best match.