[Solution] - Error: LOGIN authentication failure [SMTP: STARTTLS failed (code: 220, response: ready for tls)]

I was remodeling my e-mail infrastructure and I ran into an issue about my PfSense TLS emailing.I had this error :

My configuration looks nice

Uncheck "Secure SMTP" for STARTLS

PfSense isn't that good for providing email logs, so I decided to go deeper with a packet analysis. In Diagnotics => Packet Capture

Focusing on LAN interface and HOST 10.0.0.43 (my internal email server)

I pressed start, tested the email notification and stopped, then opened the downloaded .cap with wireshard.

"Unknow CA", PfSense was rejecting my certificate because the CA is unknow, first I was like : how is it possible, I imported it in the Cert manager and then I remembered that it doesn't help for OS checking.

I added the CA this way :

https://blog.lbdg.me/freebsd-adding-self-signed-certificate-authority/

And :)