95% of reps will just fire off templates the size of short novels with what their company does, who they work with, what industries they're in, and most of the time will end with the rep asking for a busy decision maker to take time out of their day to hear a sales pitch. It baffles me how people expect a positive response to this. You aren't providing any value whatsoever, and you're pretty much sending out spam. Don't believe me? Google the definition of spam.

irrelevant or inappropriate messages sent on the Internet to a large number of recipients.

How do you avoid this? Do your research and personalize. If you fire off a template email that goes on for paragraphs about what you do and the companies you work with and ask the person to call you back, chances are you're not building any interest. The last thing on a DM's mind is your product. What they care about is how to fix the problems they face currently. This ties back into your research.

E.G: You sell a widget shipping service. You learn from an employee that their current shipping service is slower than advertised during busy seasons, and sometimes shipments will be late or forgotten altogether. When you email the warehouse manager, mention that you spoke with this employee about this situation and that your service works with widget producers to guarantee on-time shipments, even during peak seasons. Then mention that you will call THEM to discuss, not the other way around.

You are much more likely to get a response to something relevant as opposed to a "shot in the dark" hoping that someone may not even be qualified will call you back. I've made it a personal policy to never send out bulk emails, and I usually get a 80% open rate and 30% response rate when I craft a well-thought email.