S/MIME Exchange Online

Question

Hello,

i want to setup S/MIME for a test user.
I requested a free S/MIME certificate from https://www.dgn.de/e-mail-zertifikat-dgncert/
I uploaded it via powershell to Exchange online as an .sst . The environment is cloud only. Nothing on-premise.
The certificate is there but i cannot use it wether i outlook web or mobiles.
Last command i did is:
$sst = Get-Content <sst file copied from the box>.sst -Encoding Byte
Set-SmimeConfig -SMIMECertificateIssuingCA $sst
What am i missing?

Answer 1

Hi @Alexander Tiemann

Did you follow the steps of Scenario 1 in this link: How to Configure S/MIME in Office 365
You may need to also publish user’s certificate to the Exchange Online GAL (Global Address List) using Outlook (step 4).

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Answer 2

Thank you i missed the publishing. Now it works!