Postmark is an email spam testing tool. Postmark’s sending infrastructure works to quickly, and accurately deliver the user's transactional emails to their customers’ inboxes. There is an API available which helps users to score the quality of their outbound emails.
MailTester.com allows you to verify if an e-mail address is valid or not.This can help you keep your contacts database up to date.MailTester performs a series of tests (DNS lookups, SMTP checks) on an e-mail address to determineEmail Spam Testing Tools Mail Tester
The Spam Score is a number assigned to each email by applying a set of rules and it is filtered by the spam firewall. The score is established based on a number of spam filtering tests performed on each email. The higher the SpamEmail Spam Testing Tools