 It was first published in 2006 as RFC 4550, and updated in 2009 as RFC 5550.Unlike many other mobile email proposals, including Push-IMAP, the Lemonade Profile does not provide for message submission via IMAP, but instead allows the MSA to pull message data directly from the IMAP store in a secure manner.This allows the protocols to continue to leverage the vast body of work on SMTP, and also means that any traditional IMAP client can interoperate fully with a Lemonade service.