I don't know of any reputable companies that provide free email lists. If any such businesses exist, someone please provide examples.

It's much more likely that companies providing free lists are spammers. Address skimming software is available, but beware, failure to meet the EDM conditions can land the user in legal trouble. You cannot simply send a message to a group of random businesses without consequences. A likely outcome is having your messages labelled as spam and subsequent blockage of your account.

However, there are certainly ways to legitimately collect email addresses. Both are time-consuming. Either have people opt-in as recipients or manually collect from businesses associated with yours. You can hire someone to do this for you, but then it's no longer free.

Finally, you can buy or hire email addresses from DM list providers. In my experience, it's not cheap, but by far the safest way to conduct mass mailings.

There are plenty of companies out there that offer free email lists.  @Jef Lippiatt @Sonja Ceri @Daniella Pozzolungo @Steve Osborne - what's your experience?