In view of the recent terrible case of the murder of six children in a house fire in Derby by their own father &mother, I can well imagine they will receive a lot of "Hate-Mail", which may well add to their punishment. Would they be allowed to receive such mail ??
The prison service does not say where any particular prisoner is being held. Yes I know the papers have Phillpots jail named but that is not official information it is what the reporters have found.
To get mail to a prisoner you need their prison number and jail to be sure the mail gets to them, these are not normally released to the public.
You can send a letter C/O The Prison Service and ask them to pass it on to a named prisoner and as long as they can definately identify him / her they will pass it on. They will not tell you if the prisoner accepted it though and the prisoner does not have to reply. The prisoner is allowed to get any mail sent to them but if there are security concerns the letters may be opened by the prison governor or warders.
An example, when Ian Brady 'The Moors murderer' was on hunger strike protest against not being allowed to commit suicide, he was sent loads of food in the post. People did not want him to die and so have an end to his suffering. There was even a 'send Brady a pie' campaign by a well known newspaper.