The remote host is missing an update to the system as announced in the referenced advisory FreeBSD-SA-03:13.sendmail.asc

Upgrade your system to the appropriate stable release or security branch dated after the correction date https://secure1.securityspace.com/smysecure/catid.html?in=FreeBSD-SA-03:13.sendmail.asc

FreeBSD includes sendmail(8), a general purpose internetwork mail routing facility, as the default Mail Transfer Agent (MTA). A buffer overflow that may occur during header parsing was identified. NOTE WELL: This issue is distinct from the issue described in `FreeBSD-SA-03:04.sendmail' and `FreeBSD-SA-03:07.sendmail', although the impact is very similar.