How to develop an IMAP server interface, are there libraries?

I need to create a message storage server using IMAP. Is there a Java API / library that allows me to do this?

I know there are several IMAP servers available like Apache James or Dwarf, but I don't want a complete email product, I want to be able to change what the uppon server does by receiving IMAP commands (folder management, etc.). .).

Thanks in Advance