What are pro tips to optimize email deliverability from HubSpot?
Matthew Whittaker
Co-founder & CTO, Suped
Published 2 Jul 2025
Updated 18 Aug 2025
6 min read
Taking over an existing email program within HubSpot presents a fantastic opportunity to fine-tune deliverability. My goal is always to get emails into the inbox reliably, avoiding spam folders or blocklists (or blacklists). This requires a multi-faceted approach, combining technical configurations with strategic content and list management.
When I approach a new HubSpot account, the first thing I assess is the current state of its email sending infrastructure. This means diving deep into how emails are authenticated and the quality of the sending reputation. These foundational elements directly impact whether your messages are seen as legitimate by internet service providers (ISPs).
From there, I move into the more dynamic aspects of email marketing, such as list health, engagement patterns, and content relevance. Even with perfect technical setup, poor list hygiene or irrelevant content can quickly undermine your efforts. It's a continuous process of optimization, learning, and adaptation.
Establish foundational email authentication
A robust technical setup is the bedrock of good email deliverability. Without proper authentication, even the most engaging emails might not make it to the inbox. I always ensure that HubSpot is correctly configured to send emails on behalf of my domain.
This involves setting up SPF, DKIM, and DMARC records in your DNS. These protocols verify that your emails are legitimate and prevent spoofing. HubSpot provides clear instructions for this, but it’s crucial to double-check that all records are correctly published and aligned, as misconfigurations can severely impact your deliverability. If you need assistance with DMARC, SPF, and DKIM setup, refer to our simple guide.
Key authentication considerations
DKIM setup: DKIM (DomainKeys Identified Mail) is essential for email authentication. It allows a sender to cryptographically sign emails, which receiving servers can then verify. HubSpot has a good guide on what you need to know about DKIM.
SPF alignment: Sender Policy Framework (SPF) helps prevent spammers from sending messages on behalf of your domain. Ensure your SPF record includes HubSpot's sending servers. Correct SPF alignment when using HubSpot is critical.
DMARC policy: DMARC (Domain-based Message Authentication, Reporting, and Conformance) builds on SPF and DKIM. It tells receiving servers what to do if an email fails authentication and provides valuable reports. I always aim for a policy of p=reject or p=quarantine once everything is stable.
Understanding whether your HubSpot account uses a shared IP address or a dedicated IP address is also important. A shared IP means your sending reputation is influenced by other HubSpot users on the same IP. While HubSpot manages these IPs carefully, a dedicated IP offers more control over your reputation, especially for high-volume senders. If you are sending marketing automation emails, you may be on a shared IP.
Maintain a healthy audience and list hygiene
Even with perfect technical settings, poor list hygiene can tank your deliverability. Sending to unengaged or invalid addresses leads to bounces, spam complaints, and eventually, a damaged sender reputation. I regularly clean my lists and focus on engaging with active subscribers.
HubSpot's segmentation tools are invaluable here. I create segments based on engagement, such as contacts who have opened or clicked an email within the last 3-6 months. I then prioritize sending to these highly engaged segments. For inactive contacts, I consider re-engagement campaigns or, if no response, removing them from my active sending lists entirely. This proactive approach helps to avoid spam traps and improve deliverability overall. Learning how to avoid spam traps is key.
Engaged contacts
Double opt-in: Implementing double opt-in (where subscribers confirm their subscription via email) is a gold standard. It ensures genuine interest and significantly reduces bounce rates and spam complaints. Read about a marketer's guide to spam filters on the HubSpot blog.
Suppression lists: Regularly suppress contacts who have hard bounced, unsubscribed, or consistently not engaged. Sending to these contacts wastes resources and harms your sender reputation.
Another crucial aspect is managing expectations regarding email frequency and content relevance. Over-sending or sending irrelevant emails can quickly lead to unsubscribes and spam complaints, both of which negatively impact your reputation and overall deliverability. I strive to find the right balance for each audience segment.
Craft compelling content and personalize emails
The content of your emails plays a huge role in deliverability. Engaging content keeps subscribers interested, leading to higher open and click-through rates, which signals positive engagement to ISPs. I always focus on providing value to the recipient.
Personalization is key within HubSpot. Utilizing personalization tokens to address subscribers by name or tailor content based on their preferences can dramatically improve engagement. Beyond just names, consider segmenting your audience and sending targeted messages that resonate with specific interests or behaviors. This improves relevance and helps to increase email click-through rate.
Good practice
Bad practice
Clear subject lines that accurately reflect email content.
Using misleading or overly promotional subject lines.
Providing a clear call to action and easy unsubscribe link.
Hiding the unsubscribe option or making it hard to find.
Optimizing emails for mobile responsiveness and fast loading.
Sending image-heavy emails that load slowly on mobile devices.
Using A/B testing to optimize subject lines and content.
Relying on generic templates without testing or personalization.
Avoiding spam trigger words is also important, although modern spam filters are far more sophisticated than simply flagging keywords. Focus on natural language and avoid excessive capitalization, exclamation points, or overt sales language that could trigger filters. Always prioritize delivering real value to your audience.
Monitor performance and adapt your strategy
Continuous monitoring and testing are non-negotiable for maintaining high deliverability. HubSpot offers built-in analytics, but it's important to look beyond just open and click rates.
Pay close attention to your bounce rate, complaint rate, and unsubscribe rate. A high bounce rate indicates a stale list, while high complaint or unsubscribe rates signal that your content or frequency isn't meeting audience expectations. Regularly checking these metrics helps identify potential issues before they become major problems. It's crucial to understand why your email deliverability rate is wrong if you are experiencing issues.
Key metrics and tools to monitor
Email health tool:HubSpot's Email Health tool provides a comprehensive overview of your email performance and helps identify areas for improvement.
Bounce types: Distinguish between hard bounces (permanent delivery failures) and soft bounces (temporary issues) to take appropriate action.
Blocklist (or blacklist) status: Periodically check if your IP or domain is listed on any major email blocklists. Being on a blocklist can severely hinder your deliverability. You can use a blocklist checker or implement blocklist monitoring to stay informed.
Email testing: Before large sends, utilize email testing tools to preview how your email appears across different clients and identify any potential deliverability issues. Email testing best practices are important.
Regularly reviewing your email performance allows you to adapt your strategy. If certain campaigns consistently underperform in terms of deliverability, it's a sign to adjust your content, targeting, or sending frequency. Staying proactive is the best defense against deliverability challenges.
Views from the trenches
Best practices
Ensure all technical authentication, including SPF, DKIM, and DMARC, is correctly set up for your sending domain in HubSpot.
Segment your audience based on engagement and send targeted content to active subscribers to maintain a high sender reputation.
Regularly clean your email lists by removing inactive, bounced, or unengaged contacts to reduce spam complaints.
Prioritize creating valuable, relevant, and personalized content that encourages opens and clicks, signaling positive engagement.
Common pitfalls
Overlooking domain authentication settings, leading to emails failing DMARC and landing in spam or being rejected.
Sending emails to an entire database without segmentation, resulting in low engagement and high complaint rates.
Neglecting list hygiene, which increases bounce rates, hits spam traps, and damages sender reputation over time.
Using generic, unpersonalized content or excessive promotional language that triggers spam filters and disengages recipients.
Expert tips
Continuously monitor your email health metrics within HubSpot, paying attention to bounce, complaint, and unsubscribe rates to spot trends.
Implement double opt-in for new subscribers to ensure high-quality, engaged contacts from the start.
Warm up new domains or significantly increased sending volumes gradually to build a positive sending reputation with ISPs.
Conduct A/B testing on subject lines, content, and calls to action to understand what resonates best with your audience and optimize performance.
Marketer view
Marketer from Email Geeks says to inquire if you are on a shared IP address or a dedicated IP address because using a shared IP means sharing reputation with others.
2023-07-06 - Email Geeks
Marketer view
Marketer from Email Geeks says to identify any problems you are currently observing and what you are measuring or monitoring in your existing program.
2023-07-06 - Email Geeks
The path to better inbox placement
Optimizing email deliverability from HubSpot is an ongoing effort that blends technical expertise with strategic marketing practices. By focusing on strong authentication, rigorous list hygiene, engaging content, and continuous monitoring, you can significantly improve your inbox placement rates.
Remember, every email sent contributes to your sender reputation, so consistency in applying these pro tips will yield the best long-term results. Proactive management is always more effective than reactive troubleshooting.
HubSpot presents a fantastic opportunity to fine-tune deliverability. My goal is always to get emails into the inbox reliably, avoiding spam folders or blocklists (or blacklists). This requires a multi-faceted approach, combining technical configurations with strategic content and list management.
