The remote host is vulnerable to a buffer overflow
The remote host is running a version of the Mutt email client that may be vulnerable to a buffer overrun. Specifically, it has been reported that Mutt does not handle remote internationalized folders properly. Because of this, it is possible for a malicious server to launch an attack that could result in the execution of code as the mutt user.
Upgrade to either 1.4.1 or 1.5. Patches/upgrades are available at www.mutt.org