title: What does exactly *.* mean when used in IMAP command?
body: <p>I know that using * in IMAP FETCH Command either defines all or one mail but does 
  "*:*" also defines all mails in the selected folder? Does it defines something else too? Asking cause my company is implementing its own IMAP server, and I couldn't find any reference to *:* in the RFC 3501 and 4466. </p>
  
  <p>If possible, please also cite the RFC.</p>