It is possible to send and receive mail by Mail adapter same as the normal mail server when POP3/IMAP4 service (reception) and SMTP service (Send) is started in Lotus Notes/Domino.
When POP3/IMAP4 and SMTP service is not started then, you cannot send and receive mail by Mail Adapter via Lotus Notes/Domino.
You can extract the received mail data as notes data with Lotus Notes/Domino adapter even for which POP3/IMAP4 service has not started.