If that's the case, try: printf 'Subject: TestnHello' | sendmail -f second test form specifies the 'from' address as you, but can be changed to anything you want as long as it passes muster with your provider's server. Relayhost = # (you can use :port, such as :587)smtp_sasl_auth_enable = yessmtp_use_tls = yessmtp_enforce_tls = yessmtp_sasl_security_options =smtp_sasl_tls_security_options =smtp_sasl_tls_verified_security_options =smtp_tls_loglevel = 2 # optional if you wan to see what's going on with the TLS negotiation in /var/log/mail.logsmtp_sasl_password_maps = hash:/etc/postfix/smtp_sasl_passwordssmtp_tls_per_site = hash:/etc/postfix/smtp_tls_sitestls_random_source = dev:/dev/urandomCreate /etc/postfix/smtp_sasl_passwords with the following contents: username:passwordCreate /etc/postfix/smtp_tls_sites with the following contents: MUST_NOPEERMATCHThen run the following commands: $ cd /etc/postfix$ chmod go-rx smtp_sasl_passwords$ postmap smtp_sasl_passwords$ postmap smtp_tls_sitesTo test, try: echo 'Hello' | mail -s 'Test' above test may not work if your provider requires a valid source e-mail address.

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