fix(email-service): explicitly declare optional field

[evanhutnik]

Summary

explicitly declare optional field so we don't get errors

Screenshots, GIFs, and Videos

[seanaye]

Could we write a test case for this to avoid future regressions?

EDIT: fine to do as a follow up PR, but we should make a ticket so it doesnt get lost

[evanhutnik]

Could we write a test case for this to avoid future regressions?

i had to pull over to make this fix, i will later