Are you the owner of imaplib2?

If so, you need to ensure that there are no licencing or copyright issues preventing imaplib2 being transferred into the stdlib. That may (or may not) require you to get agreement from any contributors to the library. That will depend on the licencing agreement your contributors have with you.

If you are not the owner, then you need to get the owner's agreement first, before you do anything else. We're not going to just *take* the library, or fork it.

That means that the imaplib2 library will have to adhere to Python's release schedule, our code of conduct, our policies on backwards compatibility, etc.

If the owner(s) agree that they are interested, then you can propose the idea on the Python-Ideas mailing list for discussion:

https://mail.python.org/mailman3/lists/python-ideas.python.org/

If there is interest in your proposal, then you can ask for a core developer to sponsor a PEP. Once you have a sponsor, you can write a PEP, and the steering council will rule whether or not to accept it.