Technical Tip: How to troubleshoot automation email alert with debug code: 221

[jballini]

Description	This article describes how to interpreter debug output with code 221
Scope	FortiGate
Solution	In this scenario, Customer has set up automation in FortiGate to receive an email when someone log in with SSL VPN. To investigate, the below debug was run from FortiGate CLI to isolate the issue: diag debug reset diag debug enable diag debug console diag debug console timestamp enable diag deb application alertmail -1 Once the issue is reproduced the debug can be disabled: diagnose debug disable  The above debug shows the below output with code 221: 2025-02-21 15:54:35 session finined 2025-02-21 15:54:35 _session_on_destroy 2025-02-21 15:54:35 <== send mail failed, m = 0xbd867e0 s = 0xbd73610 2025-02-21 15:54:35 session: 0xbdbffc0, rsp_state: quit, code: 221 2025-02-21 15:54:35 session finined 2025-02-21 15:54:35 _session_on_destroy 2025-02-21 15:54:35 <== send mail failed, m = 0xbd53f70 s = 0xbdbffc0 2025-02-21 15:54:35 session: 0xbd64ef0, rsp_state: quit, code: 221 2025-02-21 15:54:35 session finined 2025-02-21 15:54:35 _session_on_destroy In this context code 221 refers to an SMTP response code: '221 Service closing transmission channel'. This indicates that the email server is closing the connection after completing the email transmission process. In this example, the user checked from FortiGate GUI under System -> Settings. In the 'Email Service' section, the SMTP was enabled (Use custom settings). SMTP was enabled, the user disabled SMTP and could receive the email as desired. Issue isolated to the SMTP. Related documents: Use FortiGate automation stitches for alert emails