Use Sendico SMTP mailbox for local notifications (#57)

backend/notifications/email/failure.go

@@ -46,7 +46,6 @@ func providerFailure(body, request []byte, secrets ...string) (string, string) {
 			secrets = append(secrets, numbers.FindAllString(value, -1)...)
 		}
 	}
-	sort.Slice(secrets, func(i, j int) bool { return len(secrets[i]) > len(secrets[j]) })
 	name := safeErrorText(dto.Name, secrets)
 	if !errorName.MatchString(name) {
 		name = ""
@@ -76,11 +75,14 @@ func requestStrings(value any) []string {
 }
 
 func safeErrorText(text string, secrets []string) string {
+	sort.Slice(secrets, func(i, j int) bool { return len(secrets[i]) > len(secrets[j]) })
+	var replacements []string
 	for _, secret := range secrets {
 		if secret != "" {
-			text = strings.ReplaceAll(text, secret, "[redacted]")
+			replacements = append(replacements, secret, "[redacted]")
 		}
 	}
+	text = strings.NewReplacer(replacements...).Replace(text)
 	text = addresses.ReplaceAllString(text, "[redacted-address]")
 	text = urls.ReplaceAllString(text, "[redacted-url]")
 	text = tokens.ReplaceAllString(text, "[redacted-token]")