How can I diagnose and fix deliverability issues in Salesforce Marketing Cloud?
Michael Ko
Co-founder & CEO, Suped
Published 19 Jun 2025
Updated 16 Aug 2025
6 min read
Email deliverability in Salesforce Marketing Cloud can be a complex beast, but it’s far from insurmountable. When emails start landing in spam folders or fail to reach their intended recipients, it can feel like a daunting task to pinpoint the exact issue. This often involves digging into various aspects of your email program, from technical configurations to content and sending practices.
My goal here is to help you understand how to diagnose and effectively fix these deliverability challenges. We'll cover key areas like email authentication, sender reputation, bounce management, and list hygiene, all within the context of Salesforce Marketing Cloud. By systematically addressing these points, you can significantly improve your inbox placement rates and ensure your messages get to where they need to go.
Understanding the basics of SFMC deliverability
Salesforce Marketing Cloud provides a robust platform for email marketing, but its effectiveness heavily relies on adhering to core email deliverability principles. Simply having access to the platform doesn't guarantee inbox placement; your sender reputation is paramount. This reputation is built over time based on how recipients interact with your emails and how well your technical setup aligns with internet service provider (ISP) requirements.
A fundamental aspect of ensuring good deliverability is proper email authentication. This includes setting up SPF, DKIM, and DMARC records for your sending domains. These protocols verify that your emails are legitimate and prevent spoofing. Without them, mailbox providers like Salesforce or other major providers are more likely to flag your emails as suspicious or outright spam them.
Understanding how these work is crucial for any sender. For example, DMARC builds upon SPF and DKIM to provide instructions to receiving servers on how to handle emails that fail authentication. Implementing these correctly is the bedrock of good deliverability, and it's a common area where issues arise for many senders.
The importance of email authentication
Properly configuring your SPF, DKIM, and DMARC records is non-negotiable for anyone using Salesforce Marketing Cloud. These records are your digital signature, telling mailbox providers that your emails are legitimate and not imposters. Without them, your emails are far more likely to be sent to the spam folder, regardless of your content or sending practices. It is always important to monitor your DMARC reports to catch any authentication failures early.
Diagnosing deliverability issues
When you notice a drop in your inbox placement or an increase in bounces, the first step is always diagnosis. Salesforce Marketing Cloud provides several reporting tools that can help you identify where the problem lies. Pay close attention to your bounce rates, complaint rates, and open rates. A sudden spike in bounces, especially soft bounces with specific SMTP codes, or an uptick in spam complaints, signals a problem. You can usually find these metrics within the email studio or via custom reports in SFMC. Understanding why your emails fail is key to finding a resolution.
Another crucial diagnostic step is to check if your sending IPs or domains are listed on any email blocklists (also known as blacklists). Mailbox providers often consult these lists to determine whether to accept or reject incoming mail. If you find yourself on one, it's a clear indicator of a significant deliverability problem. Salesforce Marketing Cloud doesn't directly provide a blacklist checker, so you'll need to use external tools.
Beyond technical metrics, consider your audience engagement. Low open rates and click-through rates, coupled with high unsubscribe rates, tell mailbox providers that your content isn't relevant or desired. This can negatively impact your sender reputation, leading to more emails being routed to spam. Mastering deliverability involves understanding this interplay between technical setup and user interaction.
Metric
Implication
SFMC Location for Diagnosis
Bounce rate
High rates indicate bad addresses, spam traps, or blockages. Can severely hurt reputation.
Email Studio > Tracking > Overview; Data Views
Complaint rate
Users marking emails as spam. Crucial negative signal for ISPs. Aim for below 0.1%.
Email Studio > Tracking > Overview (for each send)
Open rate
Indicates engagement. Declining rates suggest disinterest or inbox placement issues.
Email Studio > Tracking > Overview
Click-through rate (CTR)
Another strong indicator of engagement. Low CTR can affect sender reputation.
Email Studio > Tracking > Overview
Technical issues
These often involve misconfigurations or external factors impacting your sending infrastructure.
Authentication failures: Incorrect or missing SPF, DKIM, DMARC records.
DNS issues: Problems with your DNS records affecting mail routing.
Content & audience issues
These stem from how you acquire and engage your subscribers and the quality of your email content.
Poor list hygiene: Sending to old, unengaged, or invalid email addresses (potential spam traps).
Low engagement: Recipients aren't opening or clicking, leading to negative reputation.
High complaint rates: Too many people marking your emails as spam.
Spammy content: Use of certain keywords, excessive images, or poor formatting.
Fixing common deliverability problems
Once you've diagnosed the root cause, it's time to implement fixes. For issues related to list hygiene, the most impactful step is to regularly clean your subscriber lists. Remove inactive subscribers, hard bounces, and any known spam trap addresses. Salesforce Marketing Cloud's email deliverability best practices emphasize this. Segment your audience to send targeted content to engaged users, and consider re-engagement campaigns for those who have become dormant.
For technical authentication issues, work with your IT team or Salesforce support to ensure your SPF, DKIM, and DMARC records are correctly configured. Verify that all includes in your SPF record are valid and that your DKIM keys are published and match. If you're on a shared IP, ensure your email content and sending behavior don't negatively impact other senders using the same IP, as this can affect your deliverability (or vice-versa). Moving to a new IP or subdomain without addressing underlying issues is a temporary fix at best.
Improving content and sending behavior is also vital. Avoid spammy keywords, use clear calls to action, and personalize your messages. Slowly increase your sending volume for new IPs (IP warming) to build a positive reputation with mailbox providers. Remember that mailbox providers prioritize emails from senders with consistent, positive engagement over large, sudden blasts. If you're encountering specific Gmail deliverability issues, consider their new sender requirements closely.
When using a new IP address or subdomain in Salesforce Marketing Cloud, IP warming is essential. This process involves gradually increasing your email sending volume over several weeks, starting with your most engaged subscribers. This helps build a positive sending reputation with internet service providers (ISPs). Rushing this process or sending to unengaged lists can quickly lead to blocklists and poor deliverability. It's especially critical if you're experiencing Yahoo deliverability issues with a new SFMC instance.
Views from the trenches
Best practices
Maintain robust data hygiene practices by regularly cleaning your email lists.
Segment your audience and prioritize sending to your most engaged subscribers.
Consistently monitor your key email metrics, including bounce and complaint rates.
Implement a gradual IP warming strategy for any new IP addresses or subdomains.
Common pitfalls
Attempting to warm up a new subdomain without addressing the underlying root causes.
Neglecting recipient behavior and its impact on your sender reputation.
Failing to implement or correctly configure email authentication protocols (SPF, DKIM, DMARC).
Sending to old, unengaged, or purchased lists, which can contain spam traps.
Expert tips
Set up automated systems to quickly remove bad domains or unengaged subscribers from your lists.
Create automation to generate weekly reports on domain-level deliverability, opens, and clicks.
Consider a monthly
soft-sell
Marketer view
Marketer from Email Geeks says you need to take a deep dive to figure out the root cause of reputation slides and spam placement, emphasizing data hygiene and consistent sending practices.
2022-08-09 - Email Geeks
Expert view
Expert from Email Geeks says it is not advisable to immediately jump to warming a new subdomain because if the root cause is not identified, the problem will likely persist on the new domain.
2022-08-10 - Email Geeks
Next steps for sustained success
Diagnosing and fixing deliverability issues in Salesforce Marketing Cloud requires a multi-faceted approach. It's not just about technical configurations, but also about understanding your audience, maintaining clean lists, and crafting engaging content. By systematically reviewing your current setup and practices, you can identify the weak points and implement targeted solutions. Remember that deliverability is an ongoing process, not a one-time fix.
Consistent monitoring and adaptation are key to long-term success. Stay proactive by regularly checking your sender reputation, performing email deliverability tests, and analyzing your campaign metrics. This dedication will ensure your emails consistently reach the inbox and drive the engagement you need for your marketing initiatives within Salesforce Marketing Cloud.
