Easily track delivery, opens and clicks on emails sent to your customers using Mailgun or Amazon SES.
No enough resource to promote as necessary
Source, domain name, app, accounts and all related data
The project is stable. Just monitor the servers and respond to support request
Blog posts (example: https://www.mailgun.com/blog/a-guide-to-using-mailguns-webhooks)
Up pricing; add more verticals - campaigns for example
Get in touch with the owner to discuss the tech stack, market size, or just make an offer!