My organization is currently outsourcing email delivery to an SMTP service provider. We're considering bringing that back in house to deliver our own emails.
We send about 5k transaction emails per day in relation to order confirmations and shipment notifications. This kind of volume and the importance of these emails means that we need to make sure our mail server is configured as best possible to avoid the emails looking like spam.
The emails we send tend to be similar in that they are templated order confirmations so the risk is that the emails are classified as spam and we get blocked or our emails bounce.
With the outsourced email provider, we get good deliver-ability, but if we did it ourselves, we're worried that emails won't get delivered.
Our ideas so far include:
- Setting up reverse DNS correctly
- Setting up SPF records
- Domain keys (not sure if this is easy or difficult)
What are the tips & best practice to set up a mail server which can send email of this volume and avoid being classified as spam?