Enforcing STARTTLS on submission port 587

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Welcome file

The following settings will enable opportunistic TLS for inbound connections on default smtp port(25).

smtpd_tls_security_level = may

You can enforce STARTTLS on submission port e.g 587 by editing /etc/postfix/master.cf

submission inet n       -       n       -       -       smtpd -o smtpd_tls_security_level=encrypt

This will enforce STARTTLS on port 587.

Note:

  • You would also need to first generate self signed or intermediate certificate to enable inbound TLS in Postfix.

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