From 78df24a1d551a36c5dfe22a98079378c9a226455 Mon Sep 17 00:00:00 2001 From: Michael Reber Date: Sun, 22 Feb 2026 11:57:47 +0100 Subject: [PATCH] Add mandatory RFC 5322 headers and fix incorrect line endings in mailing --- pkg/web/handlers.go | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/pkg/web/handlers.go b/pkg/web/handlers.go index 0912f5c..857d032 100644 --- a/pkg/web/handlers.go +++ b/pkg/web/handlers.go @@ -2693,9 +2693,15 @@ func sendEmail(to, subject, body string, settings config.AppSettings) error { return err } - message := fmt.Sprintf("From: %s\nTo: %s\nSubject: %s\n"+ - "MIME-Version: 1.0\nContent-Type: text/html; charset=\"UTF-8\"\n\n%s", - settings.SMTP.From, to, subject, body) + msgID := fmt.Sprintf("<%d.%s@fail2ban-ui>", time.Now().UnixNano(), settings.SMTP.From) + message := "From: " + settings.SMTP.From + "\r\n" + + "To: " + to + "\r\n" + + "Subject: " + subject + "\r\n" + + "Date: " + time.Now().Format(time.RFC1123Z) + "\r\n" + + "Message-ID: " + msgID + "\r\n" + + "MIME-Version: 1.0\r\n" + + "Content-Type: text/html; charset=\"UTF-8\"\r\n" + + "\r\n" + body msg := []byte(message) smtpHost := settings.SMTP.Host