A Survival Guide for the Small Mail Server

This document is a practical guide for small organizations on whether to run in-house mail servers versus outsourcing; it details privacy and control risks of third-party email providers, recommends how to evaluate ISPs and abuse teams, explains use of Spamhaus IP/domain blocklists and DNSBLs to reject inbound spam, and provides measures to prevent outbound spam (restrict SMTP to the mail server, guard against malware, open relays, compromised accounts and webserver abuse), concluding with advice to actively monitor logs to detect and respond to problems quickly.