It returns a table where the key is the message UID and the value is a table of:
Hold - boolean indicating whether the message is held
Read - boolean indicating whether the message is marked read
New - boolean indicating whether the message is new
Draft - boolean indicating whether the message is a draft message
Answered - boolean indicating whether the message has been replied to
Flagged - boolean indicating whether the message has been flagged (starred)
Deleted - boolean indicating whether the message has been marked to be deleted
Size - size of the message in bytes
InternalTime - IMAP4 'InternalTime' of the message - usually the time the message was processed by VPOP3. In ISO 8601 format
MessageTime - time from the Date field of the message. In ISO 8601 format
Subject - message subject
FromAddr - sender's email address
FromName - sender's text name (if any)
ReplyToAddr - reply-to email address (if any)h
ReplyToName - reply-to text name (if any)
ToList - list of To/Cc recipients
Attachments - 1 if the message has attachments
Spam - spam score