At present, the only email APIs concern adding, listing and removing filters.
I would like to see API calls for:
Email account existence verification - something like mail-account_exists, which responds True or False)
Email account creation - perhaps only setting the email address, to simplify; users can set details later from mailboxes.*
Email account disabling
Email account deletion
Email account password reset - needed for an initial password after account creation, if creation allows no details.
Requesting full account info would also be nice, which could make existence verification redundant, providing a simple error response if the address does not exist.