You will need:
Sender’s surname, Initials. (Year sent) Message subject. Personal email to: name of recipient, day and month of message.
Beam, J. (2021) RE: New passwords for off-campus access. Personal e-mail to: J. Daniels, 12 June. In-text citation: (Beam, 2018)
In-text citation: (Beam, 2021)