imapproxy is a application aware (POP3/IMAP) proxy, which enables webmailers such as SquirrelMail or Roundcube to save on roundtrips by using a local low-latency connection to a mail server over a high-latency connection that is being kept open.

SquirrelMail as well as imapproxy is very outdated software and you may not want to use it. However, if you really want, you may want to compile it yourself as shown in the rest of this article.