Hello Lennart! I'm sorry to hear you're having trouble with this! The default Let's Encrypt guide we provide will save the certificate to the local machine's personal certificate store, and should automatically associate HTTPS bindings in IIS with the newly added certificate. What error are you getting with when exporting the certificate as a PFX file?

It may be easier if you post the script with the output error.

Oh, sorry. Thanks.

This is the script (ExportCert.ps1):

Get-ChildItem -Path 'Cert:\LocalMachine\WebHosting' | Where-Object { $_.hasPrivateKey } | Where-Object {$_.Subject -like "*mail.domain.com*"} | Foreach-Object {&certutil.exe @('-exportpfx', '-f', '-p', '45****************gew',$_.Thumbprint, "C:\Smartermail\Certificates\mail.domain.com.pfx")}

Bat file and error:

C:\SmarterMail\Scripts>ExportCert.bat

Powershell.exe -executionpolicy remotesigned -File c:\SmarterMail\Scripts\ExportCert.ps1

MY "Personal"

CertUtil: -exportPFX command FAILED: 0x80090011 (-2146893807 NTE_NOT_FOUND)

CertUtil: Object was not found.

That looks good to me, the only thing I see is you're trying to select it from Cert:\LocalMachine\WebHosting' instead of 'Cert:\localmachine\My' per this KB copy here:

https://portal.smartertools.com/kb/a3466/securing-smartermail-with-lets-encrypt.aspx

LE installs the certificate to the computer's local machine store, rather than the WebHosting store.