Hi @specificmoon, welcome to the community!

I see that your Hotmail/Outlook email open rate performance isn’t as good as your others. Unfortunately, the short answer here is, deliverability can be very nuanced, and as you observed, varies by each inbox provider. 

Take a look at your deliverability report in your admin here:

• Sidebar → Deliverability → Reports

This should give you a high level view of your performance comparatively across the various inbox provider.  If you’ve had a high Spam or Bounce rate for Outlook / Hotmail recently (over time), that could be a contributing factor that you may be having deliverability issues with them.  

You can click “Bounce Details” which sometimes can give you more insights on what’s happening as one of the side effects of poor deliverability is increasing amounts of emails that bounce (or because of it).

To improve deliverability, you may want to consider isolating this group (build a Segment) and take more precautions with the quality/frequency and audience whom receive your emails.  Klaviyo has a pretty decent overview/guide to this, but as I have found, the right approach requires a lot of testing and constraint and patience to gradually improve.  Here’s the guide:

• Understanding bounced emails in Klaviyo

Deliverability is like your credit score or your personal reputation, it takes time to build and to maintain - but very easy to destroy quickly if you’re not careful with your sending practices. 

Low open rates for Hotmail/Outlook compared to other email providers can be caused by several factors. Here are some potential reasons and suggestions to improve your situation:

1. Spam Filters

Outlook has stringent spam filters, which can cause your emails to be marked as spam or junk. This may lead to lower visibility in recipients’ inboxes.

Suggestions:

• Authenticate Your Emails: Ensure that your SPF, DKIM, and DMARC records are correctly set up. This helps with deliverability and reduces the likelihood of being flagged as spam.
• Clean Your List: Regularly remove inactive subscribers and invalid email addresses from your list to improve engagement metrics.

2. Email Content

Certain content or formatting can trigger spam filters. If your emails contain too many images, excessive links, or specific keywords, they may not reach the inbox.

Suggestions:

• Review Email Design: Optimize your email layout with a good balance of text and images, and avoid using spammy language.
• A/B Testing: Test different subject lines, content formats, and sending times to see what resonates best with your Hotmail/Outlook audience.

3. Engagement Metrics

Low engagement rates can signal to email providers that your emails are not valuable, leading to lower inbox placement.

Suggestions:

• Segment Your Audience: Create segments based on engagement levels and tailor your content to encourage more interaction from Hotmail/Outlook users.
• Re-Engagement Campaigns: Consider sending re-engagement emails to inactive users, offering incentives to interact with your content again.

4. User Behavior

Outlook users may have different behaviors or preferences when it comes to checking their emails. They might be less likely to open promotional emails.

Suggestions:

• Survey Your Audience: Consider sending a brief survey to understand preferences and gather feedback on what content they would find valuable.

5. Timing and Frequency

The timing and frequency of your emails can also impact open rates. If you send emails too frequently or at times when recipients are less likely to check their inboxes, it may affect engagement.

Suggestions:

• Analyze Sending Times: Review the timing of your campaigns to see if there are patterns related to higher open rates. Adjust your send times accordingly.

Here are some additional insights and strategies to address the low open rates for Hotmail/Outlook:

1. Reputation Issues

Your sending reputation may be affecting deliverability specifically with Outlook. If your domain has been flagged or if there are complaints from users, this can impact how your emails are treated.

Suggestions:

• Monitor Sender Reputation: Use tools like Sender Score or Postmaster Tools from Microsoft to assess your reputation and take corrective actions if needed.
• Reduce Bounce Rates: Address any issues that could lead to bounces, such as outdated email lists.

2. Email Frequency and Cadence

Sometimes, the frequency of your emails can be off-putting for certain recipients. If you send too many emails, subscribers may become disengaged.

Suggestions:

• Optimize Frequency: Adjust your email frequency based on engagement metrics. Consider sending fewer emails to Outlook users while maintaining quality content.
• Personalized Sending Cadence: Allow subscribers to choose their email frequency preferences when they sign up.

3. Content Personalization

If your content isn’t resonating with your Outlook audience, it may lead to lower engagement rates.

Suggestions:

• Personalize Your Emails: Use customer data to tailor content specifically for your Hotmail/Outlook subscribers. This could include product recommendations or personalized offers based on past interactions.
• Engaging Subject Lines: Experiment with different subject lines that are compelling and relevant to your audience’s interests.

4. Technical Issues

There could be technical issues impacting how your emails render in Outlook. Sometimes, HTML or CSS issues can cause display problems that deter opens.

Suggestions:

• Test Email Rendering: Use tools like Litmus or Email on Acid to test how your emails render in various email clients, including Outlook. Make necessary adjustments to ensure a clean and professional appearance.

5. Review Unsubscribe Rates

If a significant number of your Outlook subscribers are unsubscribing, this could indicate that they’re not finding value in your emails.

Suggestions:

• Analyze Unsubscribe Reasons: If possible, gather feedback on why users unsubscribe. This can provide insights into what changes may be necessary to improve engagement.
• Win-Back Campaigns: Consider creating campaigns specifically designed to win back disengaged subscribers by highlighting new offerings or changes based on feedback.

6. Engagement-Based Segmentation

Focus on creating segments based on engagement levels to tailor your messaging more effectively.

Suggestions:

• Create Targeted Campaigns: Develop campaigns specifically for users who have opened emails in the past 3–6 months versus those who haven’t. Tailor the messaging accordingly.
• Feedback Loop: Encourage users to provide feedback on the types of content they’d like to receive.

Thanks for the response, appreciate it. 

Having broken it down, January to end of July open rates for outlook/hotmail were c40% - spam rate was amber flagged at 0.33%, that’s the only ‘negative’ i can see. 

August to present, the OR has dropped to c25%. Spam has actually improved, down to 0.16%.

So could jan-jul spam rate be impacting open rates now?

I have tried to use the suggested tool sender score but i am getting the message that the domain isn’t correct? I am entering the @xxxxx.co.uk part of the email we use? Which is the same as our website domain - is this correct?

bounce rate YTD is 0.31% for outlook hotmail. There is no flag for this and is around acc average for the period.

unsub. rate for outlook is better than all other service providers.

in terms of email rendering, i typically test all emails by sending one to myself prior to customers, and i have a hotmail acc, so shouldn’t be an issue, cause any potential problems are fixed prior to send.

frequency if anything will be low, don’t send anywhere near enough. 

i shall use the other tools you cited though, so thank you. 

thanks for taking the time to respond. 

so jan-july this year open rates for outlook/hm were c4%, BUT, spam rate was .34% and flagged as needing attention. 

august onwards, spam is down to 0.16 but open rates are down also, to 25%

so this spam rate from the first half the year could be what is influencing the poor OR’s since august onwards?

outlook/ hm bounce rates year to date have been best of all providers . 

@specificmoon:

so this spam rate from the first half the year could be what is influencing the poor OR’s since august onwards?

It’s honestly very hard to know for sure, because most of these things are algorithmic and has plenty of unknown variables or factors to them - many of these best practices by so called “experts” are at best anecdotal.  What works for a huge sender like Nike.com who sends 100’s of millions of email for the last 20 years with plenty of history is not applicable to smaller brands who just started 3 years ago with a more modest list size, etc. They can get away with much more!

In other words, if we all knew the exact formula of where the line is drawn, so will the bad actors (spammers) and they will move right up to the line - so this is deliberately obfuscated to ever know exactly how it works.  Think of sender reputation like any reputation - it’s a demonstration of consistency and repeated “good behavior.”  “Good behavior” is loosely defined as people wanting, engaging, and clicking on your email.  

On the flip side, what we do know is that continuous “negative” events will contribute negatively to your sender “reputation” over time and you will start to see more bounces with negative feedbacks.  Those are all “clues” or “hints” that the inbox provider are starting to reject your emails or you’re in some kind of “probationary sandbox.”  If you go further or don’t adjust your sending patterns, you are then just penalized without explicit warning - remember, the inbox provider is trying to do what it can to protect its users from abusive senders.

Also, just to throw in a wrench, I’ve seen (again, anecdotally), lots of performance volatility for Microsoft inboxes in the last 3-6 months.  There was even a rampant period of time where there were lots of “botclicks” across many of the accounts I have access to - we assume that Microsoft might applying new technology (AI?) to improve the quality of their customers’ email experience and rapidly changing how their spam filters work.

Sorry to provide a non-answer, but the general rule of thumb here is to isolate and test and send future emails in smaller batch tests (preferably to a Segment you know will perform well) and dial it up from there over time until you’re hopefully back to where it was.  

I think Warren Buffet’s quote here is right on point:

It takes 20 years to build a reputation and five minutes to ruin it. - Warren Buffet