In case you missed it, Google and Yahoo have activated new rules for bulk mail senders, starting February 1. This means more messages in spam (double-check you haven’t missed anything!) but it may also mean that the newsletters you send to your subscribers are (or will) get caught. If you’re uncertain about your current mail practices, read on.
Bulk Mail Definition
The new rules from Google and Yahoo are primarily focused on bulk senders, which are those using mail and newsletter tools to bulk email large numbers of people at once. Technically, this category applies to those mailing 5,000 or more people at once, however, some have pointed to Google rules using the term “email sender guidelines” and speculating the send requirements for these new rules are much lower.
What does it mean for me?
If you’re someone who has a newsletter or sends mail through another group mail tool, including Google Groups, you should be tuned in.
Make sure your email authentication and security are correctly configured. These are your super-fun acronym soup: SPF (not the sunscreen), DKIM, and DMARC.
Ensure that your mailings include an “unsubscribe” button that is direct and includes a single-step process.
Make sure your content isn’t spammy. For Google, the bar is low; if more than 0.1% of your emails are reported as spam, you may wind up being dinged and your domain blacklisted. Create good content!
Timing is Everything
While these rules have officially gone into effect, Google has stated that they will apply the rules on a sliding scale. The 1-click unsubscribe rule, for example, isn’t expected to take effect until May. And the email rejections of bulk senders will start at a small percentage of messages and grow.
That means there’s time to adjust, but keep an eye on that inbox. And if you get stuck or need support, get in touch!
The number of Gmail accounts. 
With ~8 billion people on the planet, that’s about 23% of the population with Gmail accounts.