Mailook VS WP Email Delivery

Mailivery - Reach the Inbox, not the spam folder.

Sidemail - The simplest way to send transactional emails. Sidemail makes sending transactional emails trivial, it's perfect for side projects, MVPs or the next big thing.

PromoTab - This tiny tool uses a real Gmail account to check if your emails will land in the Primary inbox of a reader or if it's stuck in the promotions tab or SPAM folder.

Postal - Open source mail delivery platform, alternative to Mailgun or Sendgrid

GMass - GMass allows you to easily schedule emails, send out mass emails and mail merge campaigns and more with Gmail! Click here to learn about more features!

Flowmailer - The email delivery platform you can rely on