Originally Posted by Crashdamage
If you want your old sent mail in your Gmail account's 'Sent' folder, simply forward the 'sent' mail to the Gmail account. Then you can move them from the Gmail inbox to the Gmail sent folder.
Nope, it won't work. The fwded mail stays in the Sending folder of the initial account, without reaching the added Gmail account
On the other hand, I'd need to do this for 2610 mails...