Clearswift MIMEsweeper 5.0.5, when it has been upgraded from MAILsweeper for SMTP version 4.3 or MAILsweeper Business Suite I or II, allows remote attackers to bypass scanning by including encrypted data in a mail message, which causes the message to be marked as "Clean" instead of "Encrypted".

MAILsweeper for SMTP 4.3.6 and 4.3.7 allows remote attackers to cause a denial of service (CPU consumption) via a PowerPoint attachment that either (1) is corrupt or (2) contains "embedded objects."