Mail_IMAP::_defaultHeaderPid()

str|FALSE _defaultHeaderPid(int &$mid, str $pid)

The header part id is determined based on which part of the message is being viewed. Attached messages, for instance have headers of their own, like the message body, these headers are retrieved using a part id. The Mail_IMAP::_defaultHeaderPid determines which is the proper part id for headers, whereas Mail_IMAP::getRawHeaders and Mail_IMAP::getHeaders selects the right headers to return or parse for the current message part.

Warning: As a method used internally by Mail_IMAP, Mail_IMAP::_defaultHeaderPid should not be used directly. Its API has the potential of being changed in future releases, should I find a more efficient approach.