Hi everyone.
First of all, I'm not skilled with Exchange, I inherited from the previous technician.
Recently I renewed my domain certificate with Let'sEncrypt. I did it the same way as always:
1) renew from Let's Encrypts app.
2) go to IIS, remove the 443 binding from Exchange Back End.
3) Restart IIS.
But this time the server doesn't receive mail. When I do a test with gmail it get's through, but I get complaints from my boss that he doesn't receive specific mail. I've added thoses emails to the whitelist but it doesn't seems to work.
When I do a "Get-MessageTracking Log", I got a huge ammount of Fail SMTP emails, but I don't know how to continue.
Thank you for your time.




