Tried Luna for my startup in the nutritionist business, to send out cold emails to look for partnership opportunities.

Luna is very simple and easy to use, they have the UX down and I would enjoy it if it worked better. There are two issues for me:
1) the suggested contacts are not good, they are not on target (i started getting suggestions for consultants) and they sometimes just go through each employee in a company (i dont want to email everyone as it's spammy, i just want to reach out to one or perhaps more sequentially) and many (for me 30-50% of emails) have invalid emails which causes bounces. This will ultimately ruin your emails reputation and get you in spam folders.
2) the suggested emails reads like total spam emails, I had to rewrite each email and while the AI picked up some of my changes - it didn't help me much compared to just adopting a template email

As I mentioned, I like the idea and this can become a great product - but for me it is not very useful at the moment