This method supports unique IDs instead of message numbers. See
{@link ezcMailImapTransportOptions} for how to enable unique IDs
referencing.
Fetches $count messages starting from the $offset and returns them as a
{@link ezcMailImapSet}. If $count is not specified or if it is 0, it fetches
all messages starting from the $offset.
Before calling this method, a connection to the IMAP server must be
established and a user must be authenticated successfully, and a mailbox
must be selected.
Example:
$imap = new ezcMailImapTransport( 'imap.example.com' );
$imap->authenticate( 'username', 'password' );
$imap->selectMailbox( 'Inbox' );
$set = $imap->fetchFromOffset( 1, 10 );
$set can be parsed with ezcMailParser