White-listing Information for MailChimp Delivery Servers

If you're sending emails to a group of people at a client company, and their email firewalls just won't let our emails get through, it's probably their email firewall. It tends to look suspicious when multiple people at one company are getting the same email at the same time. You might send this document to their IT group and ask them (very very nicely) to use the information below to white list our servers. This will hopefully prevent future delivery problems. You might even bribe them with a gift or something. This is usually all the information an IT person needs to "white list" our servers.

IPs

• 72.26.195.64/27
• 74.63.47.96/27
• 173.231.138.192/27
• 173.231.139.0/24
• 173.231.176.0/21
• 173.231.184.0/21
• 205.201.128.0/20

Updated: April 10, 2013

About MailChimp

MailChimp is an email service provider (ESP) that's been around since 2001. We've got over 3 million customers from all over the world (small business, big corporations, nonprofit groups, schools, churches, etc.) who use MailChimp to send more than 3 billion emails every month. Our servers deliver a few million emails a day, so we work very hard to keep the bad apples out, and to stay clean from abuse, to keep our overall deliverability high. Nobody's perfect, but we like to think we try the hardest.

Abuse Desk

Here's more information there about how we keep abuse off our system, and how we try to educate our users about proper email list management and etiquette:

http://www.mailchimp.com/abuse