Finding B2B email addresses of large companies seems like a really hard thing to do. The software I've looked at is either not very good or really expensive for what it does or both! Any recommendations?
It's actually really easy, if you have a budget that is reasonable and you have an expert who can deliver! Any scraping software is going to refer back a lot of junk in with the contacts you need. Problem is even if you use a mass mailer software your emails will have a horrible bounce rate and your email / IP can get blocked depending on how you send the emails.
There is a reason software is cheap. There is a reason Experian charge a fortune for quality data. Because it's worth it.
Building a quality email list of your own is the way forward. It doesn't necessarily take that long to start building a nice list.
There are also other ways to attract the clients you are looking for - content marketing for example.
