I'm afraid something is not adding up. I am interested in parameters starting smtp_ and not smtpd_ and the command does not show them. It should show some as you say you can see smtp_use_tls set so the grep should have found it. Or is smtp_use_tls commented out?

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Rather than doing screenshots as jpg's, if you use PuTTy, just selecting text from the window copies it from the terminal. (right-clicking pastes into PuTTy). You can then paste the output between code tags (the piece of paper Icon with a <> on it),
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Hi,

I ran the command on the terminal through SSH, nothing showed up. However, I took out the underscore and it listed all the features starting with stmp as show below.

You would have to add smtp_tls_security_level, but up to your post I was using "smtp_use_tls = yes" without a problem.

What do you get from:

postconf -n | grep smtp_

Hi Nick,

Thank you for your reply. I did look into /etc/postfix/main.cf file and I don't see smtp_tls_security_level option in the file. However, I do see smtp_use_tls option set to yes. Can I add this option in the main.cf file just like you have? Just wondering. Thanks.

Google "postfix encrypt e-mail" and see what you get. I have set "smtp_use_tls = yes" but looking at this I may do better to have "smtp_tls_security_level = may".