How to verify my cert expiration date on exchange 2013

i have an exchange 2013 using let’s encrypt free cert, may i ask how to check it’s expiration date of my cert running on this server?
my questions must be a very simple questions had been ask for so many time, but it appear to me that i am having problems to search the correct result from the forum here.
thanks in advance.

Hi @chemical349,

There are several options.

The client application that you used to obtain the certificate might have a way to show you the expiration.

If you have a copy of openssl and a copy of the certificate in PEM format, you can run

openssl -dates -noout -in mycert.pem

on a command line.

If the cert is used in a web service, you can visit the service with a browser and view the certificate in the browser’s security settings.

Finally, all Let’s Encrypt certificates are public and are published in Certificate Transparency. You can search Certificate Transparency with the crt.sh service at https://crt.sh/, and if you find your own certificate there, you can see all of the associated contents, such as when it expires. However, since this will show you all certificates ever issued for your service, this doesn’t give you a way to distinguish multiple certificates that may have been issued by Let’s Encrypt for the same name, unless you have some other way of knowing which of them is currently in use.

There’s most likely also a way to check this inside of the Windows certificate management tools, but I’m not familiar with those.

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