Blog article
- 8 minutes read
- Kiara Saloojee
- DMARC Enthusiast
How to check email deliverability: Tools and tips for inbox success
How to check email deliverability: Key takeaways
- Deliverability is inbox placement, not delivery rate.
- Check blacklists, bounces, and spam complaints when investigating deliverability drops.
- Improve deliverability with ongoing list hygiene, stable sending practices, and regular testing.
Knowing how to check email deliverability is essential for enterprise organizations that rely on email for customer experience and operational workflows. Even when a message is technically “delivered,” it may still end up in Spam or Junk. That is why learning how to check email deliverability is different from simply reviewing a sending report.
Email deliverability is the percentage of messages that reach the inbox. Delivery rate is the percentage of emails that are accepted by the receiving server. You can have a strong delivery rate and still have a serious deliverability problem if your messages aren’t reaching the inbox.
Poor deliverability is like paying to print and ship flyers, only to have them land straight in the bin before anyone reads them.
Use Sendmarc’s domain checker tool to confirm that the foundational authentication controls that support deliverability are in place.
Why checking email deliverability matters for enterprises
When email deliverability drops, marketing emails usually take the first hit. But the impact doesn’t stop there. It can also affect critical operational and transactional messages, like password resets, quotes, invoices, and payment links, which customers may miss if they land in Spam or Junk.
At enterprise scale, even small declines can translate into significant losses. Messages that aren’t seen don’t get opened, replied to, or acted on. That means lost revenue, higher support volume, and slower sales cycles.
Deliverability issues also create uncertainty. When open rates drop or customers say they didn’t receive an email, teams often start by adjusting what they can control quickly, like subject lines, design, or sending cadence. That work isn’t wasted. Spammy content and poor formatting can push messages into Spam or Junk.
But deliverability rarely comes down to content alone. In many cases, inbox placement issues are driven by a combination of factors, including authentication misalignment and sender reputation damage. Recipient engagement also matters because mailbox providers consider how people interact with your emails over time.
The most reliable way to diagnose the problem is to start with authentication and reputation checks, then refine content and outreach once you know your sending setup is trusted.
How to check email deliverability: Step-by-step methods
If you want a reliable process for checking email deliverability, start with the signals mailbox providers care about most.
Begin with email authentication
Email authentication is a baseline requirement for reliable inbox placement. It helps mailbox providers confirm that your email is legitimately associated with your domain.
There are three core standards to check:
- Sender Policy Framework (SPF) confirms which systems are allowed to send email on behalf of your domain.
- DomainKeys Identified Mail (DKIM) uses cryptographic signatures to verify that a message hasn’t been modified in transit.
- Domain-based Message Authentication, Reporting, and Conformance (DMARC) tells mailbox providers what to do when authentication fails. It also enables reporting, which gives you visibility into who’s sending emails on your behalf and whether those messages are passing authentication checks.
Test your domain now with Sendmarc’s free domain analyzer to identify authentication gaps that may be affecting inbox placement.
Check blacklists
Blacklists are another common cause of deliverability problems. If your sending IP or domain appears on widely used blocklists, mailbox providers may divert your messages to Spam or Junk, or reject them outright.
Blacklisting can happen for many reasons, including poor email list hygiene, sudden sending spikes, compromised accounts, or malware.
Sendmarc’s blacklist lookup tool helps you quickly check whether your domain or IP is listed, and it gives you a starting point for remediation.
Look at bounces and complaints
Bounces, spam complaints, and recipient engagement trends provide additional context. If a campaign shows unusually high bounces, it can point to list hygiene issues or sender reputation problems.
Spam complaints are especially important because they tell mailbox providers that recipients don’t want your emails. Even a small increase can reduce inbox placement over time.
How to check email deliverability in Gmail
Gmail provides admin tools that help you investigate delivery and placement issues for specific messages.
Start with Email Log Search, which lets admins search by sender, message ID, and date. This is useful when a customer or internal user reports that an email didn’t arrive, or when you want to confirm whether Gmail accepted a message and what happened to it next.
For a broader view, use Message delivery reports in the Security Center dashboard. You can filter results by traffic source, domain, and date range. If you need to share findings internally or keep a record for troubleshooting, you can also export the results.
How to check email deliverability in Outlook
If your company uses Outlook, you can investigate delivery outcomes using a few built-in features.
Delivery receipts can confirm whether a message was accepted. Keep in mind that delivery receipts confirm server acceptance, not inbox placement. If an email can’t be delivered, Outlook generates a Non-Delivery Report (NDR) with error codes, suggested fixes, and links to help materials.
For recurring Spam placement, Microsoft offers automated insights that explain common causes and suggest ways to improve deliverability.
Best practices to improve email deliverability
Once you’ve learned how to check email deliverability, the next step is improving it.
Start with list hygiene. If you regularly send to invalid addresses or disengaged recipients, mailbox providers may see your messages as lower quality. Keep lists clean by removing hard bounces, filtering out addresses that repeatedly soft bounce, and using double opt-in.
Authentication comes next. Even excellent content struggles if mailbox providers can’t confidently verify your identity. Make sure SPF and DKIM are correctly configured for every legitimate sending source, and use DMARC monitoring to spot authentication failures early.
Content still matters, but it tends to be the fine-tuning layer once authentication and reputation are stable. Keep emails relevant, avoid misleading subject lines, and maintain consistent sending patterns. Sudden spikes in volume can look suspicious, even for legitimate campaigns.
Finally, testing should be continuous. Enterprise sending environments change often as new vendors are introduced, domains are added, and configurations shift over time. Make deliverability checks a regular habit, not a one-time project.
How Sendmarc simplifies email deliverability
Enterprise email is rarely owned by one team. Most organizations have multiple systems sending email from the same domain, including marketing platforms, ticketing tools, billing systems, and customer portals.
Sendmarc helps by giving teams a single view across domains, so email authentication is easier to monitor and maintain over time.
With Sendmarc’s enterprise-grade platform, teams can view DMARC data in a clear dashboard, monitor spoofing attempts, and keep an eye on blacklisted sources. Sendmarc also supports a safe move toward DMARC enforcement, so stronger protection doesn’t disrupt legitimate email.
See how Sendmarc supports DMARC reporting, sender visibility, and a smooth path to enforcement.