1: Download EmEditor:
https://www.emeditor.com/download/
[This tool can open files upto 500GBs or even more]
2: Press: CTRL+H
3: Find: @([a-zA-Z_][a-zA-Z_0-9]*).([a-zA-Z_][a-zA-Z_0-9]*): [FOR
[email protected]:123]
OR
@([a-zA-Z_][a-zA-Z_0-9]*).([a-zA-Z_][a-zA-Z_0-9]*).([a-zA-Z_][a-zA-Z_0-9]*): [FOR...