Hi Uday, I'm super late to this question (apologies) but new here so if it's still helpful: There's far too much noise out there for bulk to work anymore. That's not to say that programmed email is ineffective. It's actually super simple to make mass messaging hit home (sincerity, personalization, offer more value than you ask for in return, etc.) but for lead gen, especially B2B as you're getting started I'd just pay a researcher/intern to pursue manual outreach and peruse Angel list for newly funded companies + crunchbase for announcements. That'll give you both a reason to reach out and a more likely prospect to contact.
I've actually done a bunch of work in the HR space (the last company I helped grow sold talent solutions), there's always demand for more candidates, so paid search is another highly converting option for you if you've got the capital to support it.
I hope these are helpful. It's hard to hear that old fashioned manual outreach is the best way to go sometimes, but when you calculate the returns on bulk email, it's actually a significantly higher ROI for your time.
You have to be more explicit about what you have done already. If you are simply spamming the universe, you will get blocked by the services or the recipients. What businesses are you trying to reach? What services do you offer.? Why would they need or want you? It is never a one size-fits all universe.
Today there are plenty of ways to reach out you could ever imagine. I'm suggesting some of them here, Social Media like Facebook, Skype, MeetUp etc. or you could connect third party bulk email providers like Mail Chimp, Constant Contact etc.
Contact the CEO's of the company. If your service is solid and adds value to their company they will listen.
My client has (we helped with branding) a product called INSTAPO that helps you send emails / voice mails / SMS from a single dashboard. Get in touch with me if you are interested.
It's against the law to send a solicitation email to anyone you do not have an existing/established relationship with or who did not request information from you (see CAN-SPAM). Even buying or renting a list of email addresses is disallowed. Scraping email addresses from web sites is also disallowed. Your options are to either co-market with someone who does have a legitimate list (advertise within their established channel), to reach the audience they developed, or to find a less regulated channel like direct mail.