I put together a really nice mass mailer, but occasionally mails end up in junkmail on various different mail providers for various reasons. Does anyone know if there is a write up anywhere on best practices to send mass mailers?
MailChimp have a good document which covers key points (IP ranges, rate limiting, SPF/DKIM, bounce handling, feedback loops).
As an aside, it's unusual to see something so comprehensive from a company whose business is based around doing this kind of stuff for other people - presumably they hope it'll make you think twice before building something from scratch!