...

Remove-ExchangeCertificate -thumbprint "C5DD5B60949267AD624618D8492C4C5281FDD10F"

Notes

Recover deleted items from any folder

1. Exit Outlook.
2. Open the Windows registry editor.
3. Browse to My Computer\HKEY_LOCAL_MACHINE\Software\Microsoft\Exchange\Client\Options.
4. On the Edit menu, point to New, and then click DWORD Value.
5. Type the name DumpsterAlwaysOn.
   1. NOTE Do not type any spaces in the name.
6. Set the DWORD value to 1.
7. Restart Outlook.

SMTP

Figure out your relay on a service provider:

...