SASL security options "."
smtp_sasl_security_options
This parameter specifies the security options that the Postfix SMTP client uses
for SASL authentication when connecting to a remote SMTP server.
The list is a comma-separated parameter of one or more of the following items:
- noplaintext: disallow methods that use plaintext passwords
- noactive: disallow methods subject to active (non-dictionary) attack
- nodictionary: disallow methods subject to passive (dictionary) attack
- noanonymous: disallow methods that allow anonymous authentication
- mutual_auth: only allow methods that provide mutual authentication (not available with SASL version 1)