In Early March 2019, Many Marketers Around the Email Industry Began Reporting and Observing Spikes in Hard Bounces for Their Email Campaigns, Particularly Around Their Yahoo Subscribers.

All signs point to another cleanse of dormant addresses by Yahoo.

Yahoo first began this practice in the Summer of 2013, where they identified user accounts that had not accessed their mailbox in over 12 months, and marked these accounts as “dormant”.  As an email marketer, sending to these addresses after they had been disabled resulted in a special bounce reply, which identified the email as a dormant address.

In addition to setting these addresses as dormant, Yahoo also made them available for reuse.  This fact is important for marketers because if a dormant email address previously signed up for your email list, and is reactivated by another user, you could potentially run into spam complaints.  You would be sending to someone that did not actually sign up to receive email correspondence from you.

To combat this, WhatCounts treats these email addresses as Hard Bounces, and will suppress them from future sends.

Thus far, we’ve seen Yahoo stick to these practices pretty much every year, and there is no evidence suggesting that they will deviate from this plan.

As a marketer, these actions align with one of the most important Deliverability Best Practices in our industry, list hygiene.

Our Deliverability Team recommends that marketers remove inactive subscribers from their lists at least once per year.  By doing this, you are able to achieve the following:

• Higher open rates by sending to active subscribers
• Increased reputation levels among the major ISPs in our space
• Reduced negative metrics (hard bounces, spam complaints, spam trap hits)

Parameters around your list hygiene should be dependent on your sending frequencies.  A daily sender shouldn’t use the same parameters as a weekly sender because those subscribers are going to be subject to different amounts of email.  Removing subscribers that have not opened in a year for a daily sender may not be aggressive enough, as those subscribers will have had to receive at least 365 emails without registering an open.  When comparing this impact to a weekly sender, the same parameter will provide a more aggressive approach, only allowing 52 sends without an open to be suppressed.

By routinely practicing list hygiene, you will likely avoid these hard bounce spikes when Yahoo conducts its next sweep of dormant addresses.

If you have any concerns over a potential impact of these bounces, our Deliverability Team offers solutions that allow you to track your inbox placement levels around Yahoo, and many other ISPs in our space.  Our team has experience implementing creative solutions, and leveraging relationships with our industry’s ISPs to resolve reputation issues and maximize the effectiveness of your campaigns.