firstnamelastname@usa.army.mil firstname.lastname@usa.army.mil

Slightly off topic fun fact, on many email clients but gmail in particular firstname.lastname@gmail.com and firstnamelastname@gmail.com are treated as the same email address as dots/periods/full stops are ignored before the @ symbol. Although this doesn’t appear to be true in all cases. I wish this were the standard because it would save a lot of confusion.