With the introduction of IPv6 in SmarterMail 11.x, there are a few security and spam checks included within SmarterMail that are exclusively IPv4 based. Below is a list of what is compatible with IPv6 from a security and anti-spam perspective.
Applies to SmarterMail 11.x - 14.x
IPv6 Anti-virus
All anti-virus measures within SmarterMail work with IPv6
IPv6 Anti-spam
Declude
SpamAssassin-based Pattern Matching
Remote SpamAssassin
Cyren
Message Sniffer
Custom Rules
Bayesian Filtering
Domain KeysDKIM
URIBL
IP-based Checks Disabled for IPv6
SPF
Reverse DNS
RBL
Other Checks Disabled for IPv6
Greylisting
Black and White Lists
DOS and Brute Force Intrusion Detection
Applies to SmarterMail 8.x - 10.x
IPv6 is not supported in these versions.