Binary package “imapproxy” in ubuntu bionic

IMAP protocol proxy

 IMAP Proxy proxies IMAP transactions between an IMAP client and an IMAP
 server. The general idea is that the client should never know that it is
 not talking to the real IMAP server while IMAP Proxy caches server connections.
 .
 IMAP Proxy was written to compensate for webmail clients that are unable to
 maintain persistent connections to an IMAP server. Most webmail clients
 need to log in to an IMAP server for nearly every single transaction. This
 behaviour can cause tragic performance problems on the IMAP server.
 IMAP Proxy tries to deal with this problem by leaving server connections
 open for a short time after a webmail client logs out. When the webmail client
 connects again, IMAP Proxy will determine if there is a cached connection
 available and reuse it if possible.