We have a job search engine which indexes around 500 jobs each day. We want to send emails to our registered users daily. The email is a newsletter composed with selected job postings from the current day. Right now we have more than 2000 registered users and we believe it will increase rapidly within next months.
Currently we are sending emails through a server which hosts our website. We send 180 mails per hour dynamically. We don't want to increase the hourly limit because we are sending important notifications and transactional emails(password reset mails, sign up mails, etc.) to users through the same server and increasing the limit might ban or blacklist the mail server.
So we bought a new SMTP server and tried to send mail with it but all of it sent to spam folder. We tried setting SPF, DKIM, DMARC records and optimizing everything. But no luck. And finally we ran some tests and learned that the service provider is blacklisted.
I know what comes into your mind now. Services like mail chimp. But we need to send dynamically generated emails with dynamic subjects and body. Each email to separate user is slightly different from each other and subject changes everyday.
I hope you understand my requirement. My question is simple. How people send massive amount of bulk email and run huge email marketing campaigns without any problem? Is there a simple solution for this kind of thing? Help is appreciated.