MAILsweeper for SMTP 3.x does not properly handle corrupt CDA documents in a ZIP file and hangs, which allows remote attackers to cause a denial of service.
Clearswift MAILsweeper for SMTP before 4.3_13 allows remote attackers to cause a denial of service (infinite loop) via an e-mail with a crafted RAR archive attached.
Clearswift MAILsweeper for SMTP before 4.3.20 and MAILsweeper for Exchange before 4.3.20 allows remote attackers to cause a denial of service via (1) non-ASCII characters in a reverse DNS lookup result from a Received header, which leads to a Receiver service stop, and (2) unspecified vectors involving malformed messages, which causes "unpredictable behavior" that prevents the Security service from processing more messages.