+LOG: H=[V4NET.0.0.0] F=<> temporarily rejected RCPT <a1@b>: unknown lookup type "<"
+>>> using ACL "a2"
+>>> processing "deny"
+>>> check hosts = 1.2.3/24
+>>> host in "1.2.3/24"? no (malformed IPv4 address or address mask)
+>>> deny: condition test failed
+>>> end of ACL "a2": implicit DENY
+LOG: H=[V4NET.0.0.0] F=<> rejected RCPT <a2@b>