Mail relay is an easy-to-use email marketing software. Their drag-and-drop email designing tool is very useful in creating new-gen responsive emails. You can also upload HTML files to the mail relay's designing feature if your organization follows a specific design pattern according to its brand kit. On the other hand, Mail relay has many free templates to adapt and design if you don't have a specific design pattern. These templates are a real help for an untrained Email designer. Mail relay's free-tier plan is one of the best in the industry. You can add 15 k subscribers and send out 75 k emails per month. After each month, you can clean the list and add new customers. Mail relay also allows you to schedule your emails. Mail relay provides useful data after each campaign. This data is useful to plan your next moves. Mail relay is easy to configure and its dashboard is filled with useful features. Mail relay has a great customer support team. Their response time is really good. Mail relay also supports SMTP emails.

The best thing is to be able to send emails to your subscribers and, thanks to the help of this tool, have them reply, buy your products, etc...

Mailrelay's free tier is so high, that it's likely that you won't paid for the service until you really grow up - and even then, its pricing is really cheap. Also, it has a ton of learning material and their support service is helpful. Watch out for their blog and their onboarding emails, they deliver a lot of useful tips and tricks. What I like the most about their blog, is that they don't only focus on giving advice on email marketing topics, they also cover digital marketing in general. Speaking more about the app, I think it's important to remark an interesting technology that they have: some time ago, they implemented "Smart Delivery", a feature that sends the emails first to the most active customers, making sure that your IP reputation is the highest possible.