Constant Contact makes it easy to automate your simple email marketing campaigns. Though, for most of the automation features, you'll have to be in their Plus plan. The Core package enables sending “Welcome Emails” when a contact first subscribes to a list. This gets the job done for downloadable lead magnets.

With Constant Contact, you can only run tests on your subject line. Mailchimp offers a lot more scope for experimentation. With Mailchimp's A/B testing, you can test up to three variations of your campaign – be it changes to subject line, body content, “from” field, send time, or any combination of the above.

Constant Contact is an email marketing and digital marketing platform that was created to help businesses create and deploy effective email campaigns that convert leads into customers easily. From within its user dashboard, users can browse and select an email template from its vast (though admittedly dated) library.

Constant Contact has a PDF-to-Email function that allows the user to upload a PDF file directly into the body of a new email template. It generates a PNG file of the first page of the PDF and will also generate a clickable button already linked to the PDF beneath the image!