We're waiting on TalkTalk to either restore the Create function or advise that new mailbox addresses are no longer offered.
As for the Delete function the user deletion of mailbox email addresses may not be possible in these current circumstances but you can give instructions for mailbox deletion to the TalkTalk Data Protection Office team.
See the GDPR help page item 'Your Right to be Forgotten / Right to Erasure '. There's a postal address, which in my view is the best way to contact the Data Protection team, but you can initiate a contact via any of the TalkTalk contact methods.
