There isn’t an answer to this question as all SMTP providers work well for cold emailing.
We highly encourage our users to make use of the list verification partners we have integrated into the software. In doing so, you will vastly reduce your bounce rate. This will keep you on good standing with your SMTP provider. Most SMTP email senders are known to flag accounts with high bounce rates, sometimes even suspending them if it continues.
Every provider will have their own pros/cons. With cold emailing, the most important thing to find is an SMTP provider that can offer high inbox rates. Messages going to spam/junk mail is one of the biggest concerns when you are sending to a list that hasn’t necessarily “opted in.”
Make sure you set your SPF and DKIM records appropriately for your mail sender. Cold emails will get inboxed better when you have setup the proper records with your DNS provider.
Additionally, make sure you follow the rules and regulations with email sending. For instance, having your company address at the bottom of the email or having an “unsubscribe” link. Even if you plan to never send another email to the list, there are laws that prevent you from removing the unsubscribe link and depending on where you live and what type of emails you’re sending, this can effect your results.