WebDefense against remote clients or servers that 'trickle' SMTP or LMTP traffic, replacing timeouts per I/O system call with per-record deadlines. Postfix 2.9. Nginx proxy support in smtpd including SASL credential passing. Postfix 2.3. DKIM, DomainKeys and SenderID authentication (via Milter plug-in) Postfix 2.3.