Based on our record, Email List Verify seems to be more popular. It has been mentiond 2 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
If you're not getting the right email addresses from ContactOut and it's bouncing back, you could always run the email addresses through something like emaillistverify.com to make sure they're valid before you try to email them. (you should do that always anyway to protect your email deliverability). Source: almost 2 years ago
Emaillistverify.com is the service I use. Source: almost 2 years ago
Waitlist API - Quick and easy waitlist with built in referral.
NeverBounce - Real-time email verification and cleaning to ensure emails never bounce.
LaunchList - Create waitlist with referral for your product launch
ZeroBounce - Removes invalid emails from your list to prevent email bounces from ruining your deliverability.
Waitlisty.io - Build excitement for your product by embedding a simple form into your website. Signups will receive a referral code to share with their friends. The more codes they share, the more they climb your waitlist.
Email Verifier - Email verifier app lets you verify email.