I don't have any Bitcoin account [...] but I got an email that I have received £46,21745 in my account
It is a lie. There's no money. It is a trick by criminals who will
later ask you to pay some fake fees that they invent.
After you realise you have been tricked, some other person (criminals also, maybe the same ones) will then contact you to offer fake ...
There are three types of spam problem in the Lightning Network. Let's
call them "local","fast" and "slow".
Local spam is someone sending or requesting too much data: that's a simple batter of code with rate limiting etc.
Fast spam is sending many failed payments. You can't tell what will succeed and you can't blame the sending ...