code: protected void acceptDynamicProperty(Postcard postcard, String bodyFile, boolean filesystem, OptionalThing<Locale> receiverLocale,
              Object dynamicData) {
          if (dynamicTextAssist == null) { // no way, just in case
              return;
          }
          final SMailDynamicPropResource resource = new SMailDynamicPropResource(postcard, bodyFile, filesystem, receiverLocale, dynamicData);
          dynamicTextAssist.accept(resource, new SMailDynamicPropAcceptor() {
              public void acceptFrom(String address, String personal) {
                  postcard.setFrom(new SMailAddress(address, personal));
              }
          });
      }
docs: ----------------