(PHP 4, PHP 5, PHP 7)
imap_lsub — List all the subscribed mailboxes
$imap_stream
   , string $ref
   , string $pattern
   )Gets an array of all the mailboxes that you have subscribed.
imap_streamAn IMAP stream returned by imap_open().
ref
       ref should normally be just the server 
       specification as described in imap_open()
      
patternSpecifies where in the mailbox hierarchy to start searching.
There are two special characters you can
pass as part of the pattern:
'*' and '%'.
'*' means to return all mailboxes. If you pass
pattern as '*', you will
get a list of the entire mailbox hierarchy.
'%'
means to return the current level only.
'%' as the pattern
parameter will return only the top level
mailboxes; '~/mail/%' on UW_IMAPD will return every mailbox in the ~/mail directory, but none in subfolders of that directory.
Returns an array of all the subscribed mailboxes.