I could not get this to work. First I opened the ‘Replace’ window using the following path:
Evolution → Message Name → 1st <no name> → 1st <no name> → 1st <no name> → 1st <no name> → 1st <no name> → Edit → Replace... → [Take Action]
Then, I used the ‘Replace’ window enter ‘you’ and ‘thou’ with this path:
Evolution → Find in Message → 1st <no name> → 1st <no name> → 1st <no name> → 1st <no name> → [Text]
When I clicked on the ‘Find and Replace’ using this path:
Evolution → Find in Message → 1st <no name> → 2nd <no name> → Find and Replace → [Take Action]
nothing happened. You was still you, not thou.