Does it look bad if I email multiple professors in the same department at once? I'm currently in the process of applying to grad schools, and I'm emailing profs whose work I find interesting. I always read a bit of their work, and then customize both, the email I send them, and the CV I attach. I discuss their work in my email, and slightly change the listed research interests in my CV to match their interests.

Often, I'll find multiple profs in the same school and department whose work I find interesting. I was wondering it its acceptable to email them all at once. Are there any potential consequences to sending out multiple emails + CVs at once to the same department, all containing slightly different research interests and repeatedly claiming I find the profs' work "fascinating"?
Yes, it does look bad. When people approach me with a generic or just marginally tailored email and do not show that they have at least thought a little bit about how their research interests possibly match mine, I just throw the email away -- if they do not put in the effort then why should I?