+const char *
+g_mime_certificate_get_valid_email (GMimeCertificate *cert)
+{
+ /* output e-mail address only if validity is FULL or ULTIMATE. */
+ const char *email = g_mime_certificate_get_email(cert);
+
+ if (email == NULL)
+ return email;
+ GMimeValidity validity = g_mime_certificate_get_id_validity (cert);
+
+ if (validity == GMIME_VALIDITY_FULL || validity == GMIME_VALIDITY_ULTIMATE)
+ return email;
+ return NULL;
+}
+