m_in_m Anglia (East) Look East
Surely if they really wanted to stop the postal entries they could just... stop? I highly doubt it's a requirement from Ofcom.

I think they do need to retain a free entry route to avoid being classed as a lottery and the regulations surrounding them.

Although you could argue that it isn't free, in that you have to pay for the stamp, although as far as ITV are concerned it is free, as they don't make any money from it.

The rules require it to be at the minimum cost possible so allows a stamp or possibly a local phone call.