-if (from) fprintf(f, "From: %s\n", from);
-if (reply_to) fprintf(f, "Reply-To: %s\n", reply_to);
-if (to) fprintf(f, "To: %s\n", to);
-if (cc) fprintf(f, "Cc: %s\n", cc);
-if (bcc) fprintf(f, "Bcc: %s\n", bcc);
-if (subject) fprintf(f, "Subject: %s\n", subject);
+if (from) fprintf(fp, "From: %s\n", from);
+if (reply_to) fprintf(fp, "Reply-To: %s\n", reply_to);
+if (to) fprintf(fp, "To: %s\n", to);
+if (cc) fprintf(fp, "Cc: %s\n", cc);
+if (bcc) fprintf(fp, "Bcc: %s\n", bcc);
+if (subject) fprintf(fp, "Subject: %s\n", subject);