"T. Valko" wrote...
It also counts cells that are numeric:

gmail...10...AAA...<empty...3M

If there might be both text and numbers then you need to add a test for
text:

=SUMPRODUCT(--(MMULT({1,1,1},--(SUBSTITUTE(LOWER(A1:P1),
{"a";"g";"m"},"")=A1:P1))<3),--(ISTEXT(A1:P1)))
....

No, better to use ISNUMBER(SEARCH(...)).

=COUNT(1/MMULT({1,1,1},--ISNUMBER(SEARCH({"a";"g";"m"},A1:P1))))