I noticed something when our Newsletter editor, Laura Roberts, began using MailChimp to send out notifications with the Guild's newsletter, The Writer's Life. I use Gmail as my primary e-mail address so this post may apply only to others who rely on Gmail.
Instead of Laura's messages showing up in my inbox, they appeared among those on the Social tab of my Gmail account. I thought I would follow Gmail's suggestions to "train" Gmail to put messages from Laura directly into my inbox, by dragging the messages from the Social tab to my Inbox, but that has failed.
So I did some digging. It turns out that MailChimp admits that it is possible messages sent through its email service providers will appear on one of the Gmail tabs introduced back in 2013--Social or Promotions. Here's what they said in an October 11, 2016, knowledge base article:
Gmail delivers messages to tabbed inboxes based on complex and changing algorithms that consider subscriber engagement, content, and sender information. Messages from email service providers, like MailChimp, often have a higher chance of being delivered to the Promotions tab.
Unfortunately, MailChimp has no control over the placement of emails in Gmail, and there is no proven way to “beat” Gmail’s algorithms. Only a subscriber can move your emails from the Promotions tab to the Primary tab.
If you rely on Gmail, watch for messages from Laura Roberts on your Social or Promotions tab. And if you don't already know how to move them from one of those tabs to your inbox, check out this article (it's easy).