Troubleshooting Tip: The email two-factor authentication code for SSL VPN client is never received

[yangw]

Description	This article describes when the two-factor authentication email code has been set up properly but never received. This issue can be identified from the debug log.
Scope	FortiGate v7.0.
Solution	The email server configuration on FortiGate has been set up properly but never received. get system email-server type : custom reply-to : DoNotReply@notification.fortinet.net <- Default setting. server : 192.168.12.14 port : 25 source-ip : 0.0.0.0 source-ip6 : :: authenticate : enable username : j51214 password : * security : none interface-select-method: auto To check more details by running the commands below: diagnose debug console timestamp enable diagnose debug application sslvpn -1 diagnose debug application fnbamd -1 diagnose debug application alertmail -1 diagnose debug enable 2024-07-02 14:18:20 [786] create_auth_token_session-Created auth token session 1738883391 2024-07-02 14:18:20 Arrived msg(type 6, 89 bytes):j51214@mail.sdd.com AuthCode: 038395 Your authentication token code is 038395.   <- FortiGate has generated a Token code. 2024-07-02 14:18:20 mail_info: from:192.168.12.14 user:DoNotReply@notification.fortinet.net  <- It was going to send mail to the client. fam_auth_send_req_internal:563 found node SSLVPN:0:, valid:1, auth:0 2024-07-02 14:18:20 mail_info: reverse path:DoNotReply@notification.fortinet.net 2024-07-02 14:18:20 [315:root:1d11]2024-07-02 14:18:20 to[0]:j51214@mail.sdd.com 2024-07-02 14:18:20 <==_init_mail_info 2024-07-02 14:18:20 create session 2024-07-02 14:18:20 resolve 192.168.12.14 to 1 IP 2024-07-02 14:18:20 ==> send mail 2024-07-02 14:18:20 connecting to 192.168.12.14 port 25 2024-07-02 14:18:20 send mail 0xa8101d0 session 0xa8413a0  ...... 2024-07-02 14:19:25 details: M.14 <donotreply@notification.fortinet.net>... Non-local sender is not allowed to relay when SMTP Auth passed <- Send mail failed caused by the local mail server is not allowing a non-local sender (DoNotReply@notification.fortinet.net). 2024-07-02 14:19:25 session: 0xa8413a0, rsp_state: quit, code: 221 2024-07-02 14:19:25 session finished 2024-07-02 14:19:25 _session_on_destroy 2024-07-02 14:19:25 <== send mail failed, m = 0xa8101d0 s = 0xa8413a0 Modified the email sender (same local domain) under the setting below and the email two-factor authentication code can be received from the email server. config system email-server     set reply-to ''noreply@mail.sdd.com" end