If it is a reply to another e-mail I write the reply message and it goes and shows up in "sent". If I try to start a conversation (i.e. not just reply to someone who has e-mailed me), I write the e-mail, press "send" and it does not show up in "sent". This staarted last night, and the messages are all of the kind which would bring an immediate reply.
I am about to run the programme. But there is now no trouble RECEIVING, it is SENDING from my account to a new contact with whom I have not been having a conversation.