There's not much information about the problem in your post, is there? Just saying 'it doesn't work' isn't much information with which anyone can help you. If you (or others) want help on these forums then a better description of the problem would be a good start. What do you see in the log files, w...

Did you try the one from Jim Dunphy?

https://forums.zimbra.org/viewtopic.php?f=15&t=60781&hilit=jdunphy+letsencrypt

https://wiki.zimbra.com/wiki/JDunphy-Letsencrypt

To start with, are all the services running? Have you tried a server reboot? What have you tried to resolve this problem?

Well, the [problem here is you haven't given any context to the error message. Does it look like spam, to whom (which service) did you send this email, have you dealt with this service before? If you want help in these forums then you have to give some idea of the exact problem and what you've done ...

Sounds like you've downloaded the NE install package, check the filename of your downloaded file.

paykocaydin wrote:I am trying to disable smtpd AUTH PLAIN login in my system.

What are you trying to achieve and why?

As this appears to be a certificate error, what have you done to check the certificates or have you even tried regenerating new certificates for your server?

La première chose à souligner est que vous devez donner quelques détails sur le problème que vous avez rencontré lors de l’installation de ZCS. Quelles ont été les erreurs que vous avez reçues et qu’avez-vous essayé de les corriger?

I don't see that error and at a wild guess I'd say there's something wrong with the certificate, have you verified that it's OK? FWIW, I'd suggest you follow the advice of JDUNPHY (Jim) and install a letsencrypt certificate and automatically update it. The script that Jim provides does that flawless...

There are several thing you could do, check the answers in this search result: https://www.startpage.com/do/dsearch?query=zimbra+redirect+https&cat=web&pl=opensearch&language=english