Currently we are using Office 2016 and our main customer base is DOD-Navy. Ever since Office 2007 went away, update a contacts digital certificate is a very very labor intense process. In addition, the Navy has gone from the @navy.mil to @us.navy.mil. The digital signature certificate that the government is issuing show is still @navy.mil. Outlook will not allow you to import or update the senders certificated due to the miss match between the email address and the email listed in the cert. How do I resolve this issue?