Mail_IMAP::_isMultipart()
bool _isMultipart(int &$mid, str $subtype)
Searches a message's structure to see if a multipart/$subtype MIME type appears, where $subtype is one of related or mixed. This is done by calling on Mail_IMAPv2::extractMIME internally. If the multipart/related MIME type appears in a message's parsed structure, Mail_IMAPv2::_scanMultipart uses the presence of that MIME type to adjust to anomolies in the message's stucture.
Warning: For most messages, the multipart/related MIME type does not appear in the parsed structure of the message. Therefore, Mail_IMAPv2::_isMultipart should not be used to determine whether a message is a multipart/related message. The Mail_IMAPv2::getRelatedParts method is provided to determine whether a message has related parts.
Warning: As a method used internally by Mail_IMAPv2, Mail_IMAPv2::_isMultipart should not be used directly. Its API has the potential of being changed in future releases, should I find a more efficient approach.
Method summary:
| param | int | &$mid message id |
| param | str | $subtype The subtype to search for. |
| return | bool | |
| access | private | |

