Just use the --include parameter, like this:
grep -inr --include \*.h --include \*.cpp CP_Image ~/path[12345] | mailx -s GREP email@domain.example
That should do what you want.
To take the explanation from HoldOffHunger’s answer below:
-
grep: command -
-r: recursively -
-i: ignore-case -
-n: each output line is preceded by its relative line number in the file -
--include \*.cpp: all *.cpp: C++ files (escape with \ just in case you have a directory with asterisks in the filenames) -
./: Start at current directory.