Gmail Mail Merge - Send personalized emails with attachments
TestSubject - Test how your email subject line displays on mobile devices.
Dynamic Campaigns by Sigstr - Share the most relevant content in every email
analyze.email - Test the spam-y-ness of your emails
Dynamically Personalized Emails by QGraph - Hyper-personalized emails for E-commerce
Rename Email - Easily change the subject of any email, by cloudHQ