diff --git a/lib/tools.js b/lib/tools.js
index 47b8d4699..eb934a7b2 100644
--- a/lib/tools.js
+++ b/lib/tools.js
@@ -873,6 +873,10 @@ MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEV3QUiYsp13nD9suD1/ZkEXnuMoSg
                     smtpConfig.tls.rejectUnauthorized = false;
                 }
 
+                if (smtpConfig.auth && smtpConfig.auth.accessToken) {
+                    smtpConfig.auth.type = 'OAuth2';
+                }
+
                 const smtpClient = nodemailer.createTransport(smtpConfig);
                 smtpClient.set('proxy_socks_module', socks);
                 response.smtp = {