(PHP 4, PHP 5, PHP 7)
imap_listscan — Returns the list of mailboxes that matches the given text
$imap_stream
   , string $ref
   , string $pattern
   , string $content
   )
   Returns an array containing the names of the mailboxes that have
   content in the text of the mailbox.
  
   This function is similar to imap_listmailbox(),
   but it will additionally check for the presence of the string
   content inside the mailbox data.
  
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.
contentThe searched string
   Returns an array containing the names of the mailboxes that have
   content in the text of the mailbox.