What tools can I use to monitor deliverability when sending emails from Microsoft Office or Google Workspace?
Michael Ko
Co-founder & CEO, Suped
Published 26 Jul 2025
Updated 18 Aug 2025
6 min read
When you're sending emails from Microsoft Office 365 or Google Workspace, ensuring they consistently reach the inbox is crucial. These platforms are designed for day-to-day business communication, but deliverability can become complex when you send higher volumes or engage in marketing activities.
The challenge lies in understanding how major mailbox providers perceive your sending practices and identifying issues before they impact your reach. While both Google and Microsoft offer some native insights, a comprehensive approach often involves a mix of internal and external tools, alongside diligent monitoring practices.
Monitoring deliverability isn't a one-time setup, it's an ongoing process. Understanding the various metrics and tools available helps you maintain a healthy sending reputation and ensure your important emails consistently land in the intended inbox, not the spam folder. I'll walk through the essential tools and strategies you can use.
Leveraging official tools
Both Google and Microsoft provide their own postmaster tools, which are indispensable for understanding how your emails are performing with their respective services. These are the primary dashboards you should be checking regularly when sending from Google Workspace or Microsoft 365.
For Google Workspace, Google Postmaster Tools provides critical insights into your sending reputation, spam rates, feedback loops, and authentication errors (SPF, DKIM, DMARC). Setting this up involves verifying ownership of your sending domain. This data helps you identify patterns and diagnose issues impacting your deliverability to Gmail recipients. You can also explore our ultimate guide to Google Postmaster Tools V2.
On the Microsoft Office 365 side, the primary resource is Smart Network Data Services (SNDS). This tool offers insights into your IP reputation, spam complaints from Outlook.com users, and blocklist data. It's essential for any sender targeting Microsoft recipients. Complementing SNDS is the Junk Mail Reporting Program (JMRP), which provides copies of emails that Outlook users mark as junk, helping you understand content-related issues.
Setting up postmaster tools
To gain comprehensive insights, you need to register and verify your sending domains with both Google and Microsoft. This typically involves adding a DNS TXT record to prove domain ownership. Once set up, regularly check these dashboards for any significant shifts in your reputation metrics or spam complaint rates, as these can be early indicators of deliverability issues.
Beyond the basic dashboards
While Postmaster Tools and SNDS provide crucial first-party data, they don't give you a complete picture of your deliverability across all mailbox providers. For a broader view, you need to monitor other key metrics and external factors.
A critical aspect of deliverability monitoring is keeping an eye on IP and domain blocklists (or blacklists). Being listed on a major blocklist can severely impact your deliverability, leading to messages being rejected or sent to spam. Many free and paid tools allow you to check if your sending IPs or domain are listed. Proactively checking these ensures you can address any listing swiftly.
In addition to blocklists, monitoring your email domain reputation is vital. This reputation is influenced by various factors, including spam complaints, bounce rates, subscriber engagement, and whether your emails pass authentication checks. A consistently good reputation signals to mailbox providers that you are a legitimate sender, which is key for reaching the inbox.
Metric
Why it matters
Tool/Method
Spam complaint rate
High rates negatively impact sender reputation and inbox placement.
Google Postmaster Tools, Microsoft SNDS
Bounce rate
Indicates issues with recipient addresses or server rejections.
Email service provider (ESP) reports
Blacklist status
Inclusion on blocklists prevents emails from reaching inboxes.
Proper email authentication is the backbone of good deliverability, especially when sending through major providers like Microsoft and Google. If your authentication isn't correctly configured, your emails are more likely to be flagged as spam or rejected outright.
You need to ensure that SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting & Conformance) records are correctly set up and aligned with your sending practices. These DNS records tell mailbox providers that your emails are legitimate and haven't been tampered with. It's a fundamental step that I can't stress enough.
While Google Workspace and Microsoft 365 handle some aspects of authentication automatically when sending directly from them, if you're using a third-party Email Service Provider (ESP) (which is common for marketing emails), you'll need to configure SPF and DKIM on your domain to authorize that ESP. DMARC, in particular, helps you monitor and enforce policies for unauthenticated emails. Implementing DMARC with a DMARC monitoring service is essential for gaining visibility into your email ecosystem and identifying potential spoofing attempts or authentication failures. For more details, consider our guide to fixing common DMARC issues.
Without proper authentication
Higher spam rates: Mailbox providers distrust unauthenticated mail, often sending it to spam.
Brand impersonation risk: Without DMARC, your domain can be easily spoofed for phishing attacks.
Reduced deliverability: Emails may be rejected outright, leading to missed communications.
With proper authentication
Improved inbox placement: Authentication builds trust with mailbox providers, leading to better deliverability.
Enhanced brand security: DMARC prevents unauthorized use of your domain, protecting your reputation.
Valuable DMARC reports: Gain visibility into all email sent from your domain, legitimate or otherwise.
Proactive measures and ongoing maintenance
Beyond the technical setup, several proactive strategies can significantly improve and maintain your email deliverability when sending from Microsoft Office or Google Workspace.
First, list hygiene is paramount. Regularly clean your email lists to remove inactive, invalid, or bouncing addresses. Sending to a clean list reduces your bounce rate and prevents you from hitting spam traps, which can quickly lead to a blocklist (or blacklist) listing. Secondly, warm up new domains or IPs if you're starting fresh or making significant changes to your sending infrastructure.
Finally, monitor user engagement metrics. Mailbox providers pay close attention to how recipients interact with your emails. High open rates, click-through rates, and low unsubscribe rates signal positive engagement, which boosts your sender reputation. Conversely, low engagement or high spam complaints can negatively impact your deliverability. Adjust your content and sending frequency based on these insights to maintain a healthy sending relationship.
Views from the trenches
Best practices
Always authenticate your sending domains with SPF, DKIM, and DMARC for optimal deliverability.
Regularly clean your email lists to remove inactive or bouncing addresses and avoid spam traps.
Monitor engagement metrics like open rates and clicks to gauge recipient interest and adapt strategy.
Common pitfalls
Sending marketing emails directly through Google Workspace or Microsoft 365 can lead to blocklisting.
Ignoring DMARC reports, missing critical insights into email authentication failures and spoofing attempts.
Neglecting list hygiene, which increases bounce rates and the risk of hitting spam traps.
Expert tips
Regularly monitor your domain's reputation with recipient-specific tools like Postmaster and SNDS.
For marketing emails, use a dedicated SMTP service provider, not directly Google or Microsoft.
Leverage DMARC aggregate reports to identify all senders using your domain, authorized or not.
Marketer view
Marketer from Email Geeks says Google has Google Postmaster Tools, Microsoft has Smart Network Data Services (SNDS), and Yahoo has SenderHub, noting that most ESPs don't send mail directly from Google Workspace or Office 365 unless it's for cold email platforms.
2024-06-21 - Email Geeks
Marketer view
Marketer from Email Geeks says clients should not send marketing emails from Google Workspace or Microsoft using services like GHL, as it will likely lead to account suspension; they should instead use a dedicated SMTP mail server for marketing.
2024-07-03 - Email Geeks
Final thoughts on deliverability monitoring
Monitoring email deliverability when sending from Microsoft Office or Google Workspace requires a multi-faceted approach. Relying solely on the native dashboards provided by these services is a start, but it won't give you the full picture.
By combining insights from Google Postmaster Tools and Microsoft SNDS with broader monitoring of blocklists, careful attention to email authentication, and proactive list management, you can significantly improve your inbox placement rates and maintain a strong sending reputation. The goal is to be proactive, identify issues early, and ensure your communication reaches its intended audience effectively. For more general advice, you can also refer to our article on how to monitor email deliverability.
Google and 
Microsoft offer some native insights, a comprehensive approach often involves a mix of internal and external tools, alongside diligent monitoring practices.
Google and 
Microsoft. This typically involves adding a DNS TXT record to prove domain ownership. Once set up, regularly check these dashboards for any significant shifts in your reputation metrics or spam complaint rates, as these can be early indicators of deliverability issues.
Google Postmaster Tools,
Microsoft SNDS
