What does a yellow status in Microsoft SNDS specifically indicate?

A yellow status in Microsoft SNDS indicates increased filtering activity for your IP address. It means a higher percentage of your emails are being subjected to spam filters or routed to the junk folder by Microsoft. This often happens during IP warming when you increase sending volume, as Microsoft's systems react by scrutinizing the new traffic more closely.

Should I immediately stop sending emails if my SNDS status turns yellow during IP warming?

Not necessarily. A single day of yellow results, especially during IP warming, might not warrant immediate action. It's crucial to cross-reference with other metrics like open rates and complaint rates. If your engagement remains strong and complaint rates are low, continue your planned sending schedule. Drastically stopping sends can sometimes hinder the warming process.

How important are open rates compared to SNDS colors when warming up an IP?

Open rates are generally more important than SNDS colors for gauging actual inbox placement. If your emails are consistently getting high open rates (e.g., above 40-50%) at Microsoft domains (Outlook, Hotmail, etc.), it's a strong indicator that your mail is reaching the inbox, even if SNDS shows yellow. The SNDS color can be a leading indicator, but real-time engagement data provides a clearer picture.

What other metrics should I monitor alongside SNDS during IP warming?

Alongside SNDS, you should monitor your open rates , click-through rates, and complaint rates. Bounce rates (especially hard bounces) are also critical. These metrics provide direct feedback on how your recipients are interacting with your emails and indicate whether your messages are landing in the inbox or the junk folder.

Can my IP return to green after being yellow in SNDS?

Yes, your IP can return to green after being yellow. This typically happens as you continue to send desired mail to engaged recipients consistently over time. Microsoft's systems will learn to trust your sending patterns. Maintaining a clean list, relevant content, and proper authentication (SPF, DKIM, DMARC) are key to improving and stabilizing your sender reputation.

How to interpret Microsoft SNDS yellow results and adjust sending during IP warming? - Sender reputation - Email deliverability - Knowledge base

Starting a new IP warming process always comes with a mix of anticipation and anxiety. We carefully plan our sending schedules, segment our audiences, and diligently monitor performance. A key tool in this process, especially for sends to Microsoft properties (like Outlook, Hotmail, Live, and MSN), is

Microsoft SNDS (Smart Network Data Services). It's designed to give us insights into our sender reputation and filtering activity.

For the first ten days of an IP warm-up, seeing all green results in SNDS is reassuring. It suggests things are going smoothly, and our emails are landing in the inbox as expected. But then, there's that moment when you log in and see a yellow result for the first time. It can feel like a sudden shift, leaving you to wonder what it means and whether you need to immediately change your carefully planned sending strategy.

The natural inclination is to panic. Should I scale back my sends? Is my IP getting blocklisted (or blacklisted)? Have I done something wrong? While these are valid concerns, it's crucial to understand what the yellow status truly signifies and how to react appropriately during the sensitive IP warming phase.

This guide will walk you through interpreting those yellow SNDS results and help you make informed decisions about adjusting your sending volume, ensuring a smoother IP warming journey.

Understanding Microsoft SNDS color codes

Microsoft SNDS provides aggregated results of the spam filtering applied to all messages sent by an IP address during a given activity period. These results are categorized into three color codes: green, yellow, and red. Each color is meant to indicate the reputation of your sending IP addresses.

Green usually signifies a good reputation, with minimal filtering or blocklisting. Yellow indicates increased filtering, meaning a higher percentage of your mail is being subjected to spam filtering or junked. Red signals a poor reputation, with a significant amount of mail being rejected or sent directly to the junk folder. This is why many senders are keen to monitor their SNDS status during IP warming.

However, the reliability of these color codes as a sole indicator of deliverability has been a subject of debate within the email community. Some email deliverability professionals suggest that the colors may not always accurately reflect actual inbox placement, citing instances where IPs with a red status still achieved good inbox delivery, while green IPs saw mail routed to spam. You can learn more about the accuracy of these reports on Laura Atkins' blog.

The nuance of yellow

A yellow status in SNDS indicates that a higher percentage of mail from your IP address is being filtered or junked by Microsoft’s spam filters. During IP warming, this is often a sign of increased volume or a slight shift in how your mail is perceived, rather than an immediate reputation crisis. It means Microsoft is scrutinizing your sending more closely.

One common reason for a transition from green to yellow during IP warming is a significant increase in sending volume, especially your first large send to a new cohort of recipients. When you send mail approaching 1,000 recipients or more on a new IP, it's not unusual for Microsoft's systems to react with increased filtering as they evaluate this new sending behavior.

Interpreting yellow SNDS results

While a yellow SNDS status might cause alarm, it’s important not to react impulsively based on a single day’s data. SNDS data is aggregated and can sometimes be delayed. Instead of immediately scaling back, consider the broader context of your deliverability metrics. If your SNDS data appears to contradict actual deliverability, a deeper look at other indicators is necessary.

The primary metrics to focus on are your open rates and click-through rates, especially for your sends to Microsoft domains. If your open rates remain high (e.g., in the mid-60s as reported by one marketer, which is an excellent indicator), it suggests your mail is still successfully reaching the inbox, even if some is being filtered or junked. A low click-through rate, on the other hand, could indicate issues with content relevance or engagement, but not necessarily inbox placement.

When to adjust sending volume during IP warming

SNDS status (yellow/red)

SNDS provides a high-level overview of your IP's reputation with

Outlook. A yellow status indicates increased filtering, but it doesn't always directly translate to emails landing in the spam folder. Its utility can be limited, and it might not always accurately reflect inbox delivery. Over-reliance on this color code without cross-referencing other metrics can lead to unnecessary adjustments during IP warming.

Key engagement metrics

Open rates and click-through rates are critical indicators of whether your emails are actually reaching the inbox and resonating with recipients. High open rates, particularly to Microsoft domains, are a strong sign of successful inbox placement. Complaint rates should also be closely monitored, as a sustained increase here is a definitive signal to adjust.

The decision to scale back your sending volume during IP warming should not be based solely on a yellow SNDS result, especially if it’s a one-off occurrence. It's more important to look for trends over several days and correlate them with your engagement metrics. If you observe a consistent dip in open rates across Microsoft properties, or a noticeable uptick in complaint rates (even if SNDS doesn't show it), then scaling back should be considered. This could indicate underlying issues with your sending practices or audience engagement. For more detailed analysis, consider how to troubleshoot Microsoft email deliverability.

During IP warming, the goal is to gradually build trust and reputation with mailbox providers. A yellow status may simply be a testing phase by Microsoft's algorithms. If you're sending truly wanted mail to an engaged audience, things generally even out over time. If you continue to see a yellow status alongside declining engagement, then it's wise to slightly reduce your sending volume to Microsoft properties or focus only on your most engaged users. However, if your engagement remains strong, you may just need to continue with your current IP warming schedule, or perhaps extend each phase a little longer.

It's important to remember that IP warming can be tricky, especially with Microsoft. For a comprehensive overview of how to manage this process, you can explore the best approach for warming up an IP.

Strategies for managing IP warming with yellow alerts

Metric	Status/Observation	Recommended action
SNDS color	Yellow (single day)	Monitor closely, do not panic. Continue current sending volume.
SNDS color	Yellow (multiple consecutive days)	Evaluate content, list quality, and engagement. Consider minor adjustments.
Open rates (Microsoft domains)	High (e.g., >40%)	Continue with IP warming as planned. SNDS yellow may be benign.
Open rates (Microsoft domains)	Significant drop	Consider pausing or slightly reducing volume to Microsoft.
Complaint rates	Low/stable	Maintain current volume. Focus on continued list hygiene.
Complaint rates	Noticeable uptick	Immediately reduce volume and review list source/content.

During IP warming, maintaining consistent sending quality is paramount. Ensure your mailing list is clean and highly engaged. Sending to your most active subscribers first helps build a positive sending history quickly. This is especially true when you're trying to resolve IP warming issues with Microsoft accounts.

Pay close attention to your email content. Avoid anything that might trigger spam filters, such as excessive images, suspicious links, or overly promotional language. Authenticate your emails properly with SPF, DKIM, and DMARC. These foundational elements signal to mailbox providers that your emails are legitimate and can significantly impact your sender reputation, helping to avoid issues like being added to a blocklist (or blacklist).

If you continue to face persistent issues, even with a clean list and proper warm-up, it might be worth investigating if there are deeper, underlying reputation issues. You can also explore how to resolve persistent IP reputation issues with Microsoft, even after rigorous IP warm-ups and maintaining clean lists.

Views from the trenches

Best practices

Monitor key engagement metrics closely: Open rates, click-through rates, and complaint rates are more reliable indicators than SNDS colors alone.

Maintain consistent, high-quality sending: Even if SNDS turns yellow, stick to your warming plan if engagement remains strong.

Focus on engaged users: Prioritize sending to your most active subscribers during warming, especially to Microsoft domains.

Common pitfalls

Panicking over a single day of yellow: One day of yellow does not necessarily mean an immediate problem or a need to halt sends.

Over-relying solely on SNDS colors: These are general indicators, not definitive proof of inbox placement or blocklisting.

Ignoring other metrics: Failing to cross-reference SNDS with open rates, click rates, and complaint data can lead to misguided decisions.

Expert tips

Review your list hygiene: Ensure you are not sending to inactive or unengaged users, which can contribute to filtering.

Segment your audience: Send your best-performing content to highly engaged segments when dealing with yellow statuses.

Consider a longer warm-up: If issues persist, extending the warm-up period for Microsoft sends can sometimes help.

Expert view

Expert from Email Geeks says: The colors in SNDS often do not correlate with actual email delivery. I have observed instances where solid red status corresponded to excellent inbox delivery, and solid green resulted in mail going to spam. Therefore, the reporting may not always reflect the true sending behavior.

2024-06-03 - Email Geeks

Marketer view

Marketer from Email Geeks says: It is important to look for trends over several days in SNDS, and monitor open rates to see if there is a dip. While green to yellow may not be significant, red typically indicates much lower open rates. Microsoft warming can be challenging.

2024-06-03 - Email Geeks

Navigating your IP warming journey

Interpreting Microsoft SNDS yellow results during IP warming requires a balanced approach. While SNDS provides valuable data, it's not the only metric to consider. The key is to avoid knee-jerk reactions and instead, focus on the holistic view of your email program’s performance.

By prioritizing strong engagement metrics, maintaining consistent sending practices, and understanding the nuances of how mailbox providers (like Microsoft) evaluate new IPs, you can navigate the IP warming journey successfully, even when you encounter a yellow status.