Show HN: A simple SMTP proxy that bridges legacy software to modern SMTP servers

CVE-2017-9801: Apache Commons Email SMTP header injection vulnerabilty

Split Tunnel SMTP Exploit Explained

Show HN: Fake SMTP server as a service

SMTP over XXE − how to send emails using Java's XML parser

POP/IMAP/SMTP/Caldav/Carddav/LDAP Exchange Gateway

Internet Draft: SMTP Strict Transport Security

Measuring SMTP STARTTLS Deployment Quality

SMTP Injection via recipient email addresses

The sad state of SMTP encryption

Bitmask 0.9.1: Automated GPG key handling, IMAP/SMTP local proxies

SMTP/Email inspector- like requestb.in or httpbin.org but for email

Google Lets SMTP Certificate Expire

Combining SMTP and HTTP tar pits to proactively reduce spam (2006) [pdf]

Zimmerman (PGP), Levison (Lavabit), release Secure Email Protocol DIME. DIME is to SMTP as SSH is to Telnet.