In Hill v. W. E. Brittain, Inc., 405 S.W.2d 803 (Tex. App.--Fort Worth 1966, no writ), although the Hills did not deny that they were actually "served with" a copy of a motion for judgment not withstanding the verdict and notice of a hearing on the motion, they complained because it was not sent to them "by registered mail as provided by Rule 21a." Id.
The court concluded that "prima facie evidence of service" and the appearance and participation of the Hills at the hearing demonstrated that the Brittain's notice by mail was adequate. Id.
The court explained that the Hills "were in no way prejudiced." Id. Moreover, the Hills made "no showing that they were denied any rights or privileges or that had service been proper, assuming it was not, that a different result would have obtained." Id.
In sum, nothing suggested that the Hills "could or would have made a better showing or presented a stronger case had they received notice by registered or certified mail rather than by regular mail." Id.