I'm currently running a web-app that will send emails to users when they sign-up, invite friends, and want to reset password. I also will be sending out general marketing email. I have a postfix server set up, but I don't have reverse DNS set up (due to hosting provider limitations). I'm afraid my emails to users will not be delivered. I've tested it and some mail go straight to the Spam box for Gmail.
Instead of this DIY approach, are there good emailing providers out there that can guarantee high deliverability of my emails? I'd rather not have to deal with this myself so I can concentrate on building my app. I looked into Mailchimp but they seem to be a service for bulk mailing and not for individualized emails (in the case of user sign up validation, friend invitation, and reset password). Or am I getting this wrong?
Ended up using SendGrid. They take care of all the deliverability issues and can do transactional email sending.