malware bytes question

i use Symantec at my work on my domain computers, but it apparently hasnt been updating the definitions on some computers. I downloaded malware bytes on those computers and have been using that. so far its been working as expected.
heres the question. ive gotten black listed by CBL a few times, and what that usually means is i have a spam email sending trojan somewhere on my network. does malware bytes stand a good chance at picking up a spammer trojan?