Oh, Microsoft

Things have been a little unsettled at Microsoft webmail properties over the last few months. A number of ESPs reported significantly increased deferrals from Microsoft properties starting sometime late in November. Others saw reduced open rates across their customer base starting in late October. More recently, people are noticing higher complaint rates as well as an increase in mail being dropped on the floor. Additionally, Return Path announced certification changes at the end of November lowering the Microsoft overall complaint rate to 0.2%, half of what is was previously.

Overall, sending mail to Microsoft is a challenge lately. This is all correlated with visible changes which may seem unrelated to deliverability, but actually are. What are the changes we know about?

1. Towards the end of 2017, Microsoft moved their free webmail properties over to the same backend as Office365.
2. Microsoft has updated their mobile interface to include this-is-spam buttons.
3. FBL reports are generated now when users move mail to the bulk folder, even when using an IMAP client.
4. Microsoft and Return Path decided to lower the acceptable complaint rate for certified IPs.

All of these changes are clear evidence Microsoft is investing in their email product and their filtering methodology.

Is it better?

I’m hearing mixed reports from folks. Many senders are seeing improvements in inboxing. However, it’s neither a consistent or linear progression. Things will improve for a while, then fall apart again. The overall trajectory is upwards, which is good; but there is frequent backsliding.

When will it be over?

I’m not sure. It may be that the new backend gives Microsoft some extra knobs and levers to dial in their filters and inboxing there will continue to be challenging. One thing I’m seeing on my clients is that Microsoft delivery is tracking closer to Gmail, or even a little worse. Senders that have traditionally struggled to reach the Gmail inbox are now starting to struggle to also reach the Microsoft inbox. This indicates that their filtering processes are focusing more on engagement and user interaction with email than before.
One bit of evidence for that is the move to more closely record feedback from mobile applications and generating FBL emails from IMAP clients. Sendgrid has a good blog post from last week discussing the increase in complaints. To me, this really confirms that Microsoft is looking at engagement and has improved their tools to better measure it.
A major problem with FBL reports is that they were only available when the ISP controlled the email interface. People who used a desktop or mobile mail client didn’t have a spam button, so even if they hated a particular mail, they couldn’t report it. Now, they have a report button in the mobile interface. On the desktop, reports are generated simply by moving messages to the spam folder. This means more complaints from recipients that couldn’t complain before.
At the same time they’re increasing the number of complaints generated, Microsoft has visibly lowered their complaint thresholds. This means more senders are going to struggle with inbox delivery, at least in the short term.

What does Microsoft say?

Many different folks attempted to discuss this with Microsoft employees, but there weren’t many answers forthcoming. One individual did report a response to one of their complaints that indicated Microsoft was seeing an overall increase in complaints. This may be due to the increase in reporting pathways, but it also might be due to the deluge of holiday mail. Many recipients react negatively to the holiday ramp up and hit spam or unsubscribe from more mail.
In all likelihood the increase in complaints is likely partially attributed to the increase in volume and the increase in reporting pathways.

What now?

As Microsoft has not published any specific information on their new filters, we’re left with seeing what has worked for senders to improve delivery. As always, send to users who want and expect your mail. Pay attention to engagement and remove recipients that show little interest in mail. Use other channels to encourage users to check their bulk folder and move the mail back to their inbox. If you’re doing all these things and not seeing improvement, talk to your deliverability team. They may see something you don’t. If your delivery team can’t help you, contact us and we’ll see what we can do.
Above all, don’t expect this to be resolved overnight. Microsoft has change how they’re doing things and it may take a few more weeks or months before their filters are dialed in exactly right. Expect changes to continue. I know it’s difficult to be patient, but sometimes there’s nothing else to do. Send good mail users want, and the filters will catch up.