The following ports can be used by all users:
Port 80 (HTTP)
Port 443 (HTTPS)
Other non-mail ports become accessible after identity verification.
The following receiving mail ports become available after $5,000+ spend and identity verification:
Port 110 (POP3)
Port 993 (IMAP)
Port 995 (POP3)
Port 143 (IMAP)
All SMTP (sending mail) ports remain inaccessible even after identity is verified.