Prevent crash

app/src/main/java/eu/faircode/email/ServiceSend.java

@@ -391,13 +391,17 @@ public class ServiceSend extends ServiceBase {
                             HtmlHelper.getPreview(body),
                             parts.getWarnings(message.warning));
 
+                    Long size = null;
+                    if (body != null)
+                        size = (long) body.length();
+
                     Long total = null;
                     List<EntityAttachment> attachments = db.attachment().getAttachments(sid);
                     for (EntityAttachment attachment : attachments)
                         if (attachment.size != null)
                             total = (total == null ? 0 : total) + attachment.size;
 
-                    db.message().setMessageSize(sid, (long) body.length(), total);
+                    db.message().setMessageSize(sid, size, total);
                     db.message().setMessageSent(sid, time);
                     db.message().setMessageUiHide(sid, false);