From ARRL Web:
12/21/2020 – The FCC is encouraging users of the Universal Licensing Service (ULS) to have an email address on file with the FCC.
“Applicants are strongly encouraged to provide an email address on their license application(s), which will trigger the electronic issuance of an official copy of their license(s) to the email provided upon application grant. Per the timing specified in Rulemaking FCC 20-126, the FCC will no longer print, and licensees will no longer be able to request, hard copy license authorizations sent by mail.”
The FCC has not yet established the date by which an email address will be required on all applications. ARRL VEC already has begun including email addresses on FCC applications for as many applicants as possible.