In today's day and age (i.e. the age of spam), mail deliverability is a critical issue. In order to assist you in getting your mail delivered, here are the current mail servers in use by Chargify:

mail2.chargify.com

One way to use this information to increase your chance for successful deliveries is to create an SPF record such as the following:

v=spf1 a mx include:chargify.com [other mechanisms you add to describe sending hosts] ~all

Note: as we strive stay on the edge of deliverability best practices, we may change our sending hosts from time to time. Please watch this page for changes.

Don't forget, you can always check to see if your SPF record is public - using a tool like the SPF Query Tool.