acSMTP 介绍
一个可运行于Windows系统下支持SMTP/POP3/IMAP的邮件服务器，多年没更新了，具备以下特性
Black/white lists for IPs/Emails, RBL spam blocks, DNS Email validation,
optional DBMS backend for lists and rules, custom user authorization,
AntiVirus API.
acSMTP 官网
http://sourceforge.net/projects/acsmtp/
