All electoral papers provided for by this Act may be transmitted
through the post free of charge to any elector or person claiming to be an
elector, subject to the regulations in force under the
Postal Services Act 1975 , and all papers so transmitted to an elector, if
duly addressed, shall, on proof of posting, unless the contrary be shown, be
deemed to have been duly served on and received by the elector to whom they
were addressed on the day when in the ordinary course of post they should have
been received at the elector's address.