Mother trapped in lie over messages (1-4)
I believe the answer is:
'mother trapped in lie over messages' is the definition.
I can't tell whether this definition defines the answer.
'mother trapped in lie over' is the wordplay.
'mother' becomes 'ma' (Ma is another word for mother or mum).
'trapped in' indicates putting letters inside.
'over' says the letters should be written in reverse.
'lie' back-to-front is 'eil'.
'ma' placed into 'eil' is 'E-MAIL'.
Can you help me to learn more?
(Other definitions for e-mail that I've seen before include "Online correspondence" , "Electronic epistle" , "Messages via the internet" , "Message sent via computer" , "Messages between computer terminals" .)