The following list is an index of various tools and methods to use for SMTP Authentication. For example, if you would like to use MySQL for authenticating your exim users, click on the link "MySQL."

• Pam
• Pam and Passwords
• pwauth (easily authenticate against /etc/shadow without running as root)
• Certificates
• Dovecot
• Courier
• MySQL
• LDAP
• IMAP
• SASLAuthd
• NTLM
• Broken Clients - Non-standard EHLO response
• Authenticated Forwarding - Using exim for authentication on smart relays
• How to make custom authenticators, e.g. for CRAM-SHA1
• Testing authentication - SMTP Client can be found at http://www-uxsup.csx.cam.ac.uk/~fanf2/hermes/src/smtpc/