title: Is there a way to combine Microsoft Serialized Certificate Store (SST) Files?
body: <p>I am trying to import multiple certificates to Outlook365 so that the Outlook web client will trust those S/MIME certificates. For reference, the command I'm using to import the SST file to Outlook365 is as follows:
  <code>Set-SmimeConfig -SMIMECertificateIssuingCA (Get-Content C:\Users\chaos\OneDrive\Documents\Personal\Folders\keys\AllImportantKeys.sst -Encoding Byte)</code></p>
  <p>However, this command appears to <strong>replace</strong> the key store with the contents of the SST file, rather than appending the keys in the SST file.</p>
  <p>The problem is that you can only export multiple certificates to an SST file if they are in the same folder in the Windows Certificate Manager. So, if you want to create an SST file that contains multiple certificates in multiple folders (for example, <code>Current User\Personal\Certificates</code> and <code>Current User\Trusted Root Certification Authorities\Certificates</code>), you are out of luck.</p>
  <p>I have exported the certificates I need from four folders to four separate SST files. Is there a way to combine or merge them? I tried a simple file concatenation with <code>Get-Content</code> piped into <code>Set-Content</code>, but I get a bad format error when trying to import the SST file to Outlook365.</p>
  <p>If SST files can't be easily combined, is there another workaround? For example, a way to force Outlook365 to append rather than replace? Or, a way to export all the keys I need at once (from multiple folders) to the SST file?</p>
  <p>Thanks!</p>