'Anonymous' has been in touch again. Thanks to those who worked out his first message. Obviously, I am terrified. This is their second email:
'Hi Sherlock
SOMNEHCCGTEKOTYRIMOOLAIGU
You'll never find out who I am. I live off the grid.
cheers
xx'
You don't need me to point out the clue there - Sherlock
Solution:
SHERLOCK I AM COMING TO GET YOU
This is a form of grid cipher. There are 25 letters in the message so it's easy to work out the factors - 5 x 5! Create a 5 x 5 grid and write the letters in the grid from left to right, top to bottom. The decoded message reads down from top to bottom, left to right!
Some anonymous guy has been sending me emails. It could be nothing but I'll post them up here. Could be an interesting case that you can help me with...