Dear @Solaire @uptime @404error ,
Thanks for your messages. The only “seems to be reliable” service we’ve found so far is Woodpecker.co - Cold Emails & Follow-Ups , but after @Jarland’s amazing advice, we’ve changed our mind about using ANY services for cold email outreaching and in addition to that, we’ve rethinked our marketing - add value first, make a decision maker warmer, follow up with a phone call.
Contacting from our non-EU, USA, developing country to the target audience’s non-EU, USA developing country, following up process seems to be very expensive, so we have decided to focus on local clients first 
Now back to your questions:
We created a very small Google Sheets document MANUALLY based on info from target audience company websites (email, CEO/Founder name, when it happens to be written there).
As I said, cold emailing outreach thing would never happen after @Jarland’s killer insights, but probably before writing an email, we have to be make sure that we have our niche website 100% relevant to the kind of business we are selling to and that this new website will 1000% change the user experience to the better in the future.
Again, we have already changed our minds thanks to @Jarland, but we wanted to personalize the email as much as possible, indicate our Full Name, Full Address, Phone Number and Email in the signature, plus, giving the email reseiver an option to reply with something like “not interested” and they would never hear from us again. If we used an email service, unsubscribe link would be there instead, I guess.