TYPO3 Core

Currently there is only a postprocessor to send emails.

One great feature from th_mailformplus (and other extensions) that people miss quite often when considering to migrate to the new form-functionality is a way to save entries to the database. In th_mailformplus thats just a simple table (tx_thmailformplus_log) that holds an entry for each submission which is basically CSV-format (first line: headers/fieldnames, second line: values).

It would be great to add a postprocessor to be able to write to the DB. One db-table for use "out of the box" should be added as well.
This might later be extended to maybe write to other DB-tables with the right TypoScript-configuration.

Although it's a "new feature" I think it might be worse to consider a backport as well to make migration of forms for users of 4.6.x easier as well.