So you want to transfer a Gmail account to another Google Mail account? There are lots of ways to do it. You could use a specialized software such as Gmvault, or use an email client such as Outlook or Mozilla Thunderbird. Lifehacker has a much easier and simpler solution to moving your emails to your new Gmail account, but it’s so old back in 2008 that the instructions don’t apply exactly anymore.
Log in to your OLD GMAIL and go to “Forwarding and POP/IMAP”. In the “POP Download” section, select “Enable POP for all mail”. Save changes.
Login to your NEW GMAIL. Go to “Accounts and Import”. “Import mail and contacts” will not work here since we are importing from ANOTHER GMAIL account. However, if you are importing from an OLD GMAIL GOOGLE APPS account, it can work.
So, in the “Check mail from other accounts (using POP3)” section, click “Add a POP3 mail account you own”.
Type in your OLD GMAIL account’s details, hit “Add Account” then WAIT. If you have a lot of email in your previous account, this will take some time. The popup screen should look like this: