Deliverability problems need a diagnosis before another campaign is sent. Authentication, recipient expectations, suppression rules and sending history all affect the result. A valid DNS setup alone does not guarantee inbox placement.
This guide sets out what I would check in a HubSpot account and what the team needs to decide. Keep the findings with the campaign operating documentation so they can be reviewed after a domain, integration or audience change.
Verify authentication on the domain you actually use
Follow the records generated by the account’s sending-domain setup, rather than copying a generic SPF value. HubSpot documents how to configure and check DKIM, SPF and DMARC authentication. If an SPF record already exists, incorporate the requested value into that record instead of creating a second SPF record.
Check a delivered message as well as the domain settings. Confirm which domain appears in the From address, which service sent it and whether authentication passes. Include every sending service in the review: marketing automation, sales outreach, product notifications and support may use different infrastructure.
Before strengthening a DMARC policy, identify legitimate senders and review authentication results with the person responsible for DNS. Treat this as a controlled infrastructure change, with an owner and a way to investigate rejected messages.
Use the receiving provider’s rules
For personal Gmail accounts, bulk senders must meet additional authentication and unsubscribe requirements. Google recommends keeping the reported spam rate below 0.10% and avoiding 0.30% or higher. Its sender guidelines explain the scope and monitoring tools.
Track trends by receiving domain where data is available. A campaign-wide average can hide a problem at one provider. If complaints or rejections increase, investigate the audience source, message frequency and recent configuration changes before increasing volume.
Separate marketing unsubscribe from transactional delivery
Gmail’s one-click unsubscribe requirement applies to marketing and promotional messages, not transactional messages such as password resets. The sender FAQ also distinguishes the required email headers from a link to a preference page. A footer link alone does not implement the header-based mechanism.
Test the unsubscribe path on an actual marketing message and verify the resulting subscription state. If another platform also sends campaigns, check that the choice reaches it. Do not label promotional content “transactional” to bypass a recipient’s preferences.
Make suppression a documented business rule
- Hard bounces: review the failure reason and the platform’s suppression behavior. A hard bounce can reflect more than a nonexistent address; avoid automatically deleting the whole CRM record.
- Unengaged audiences: agree an inactivity window that fits the sending cadence and customer relationship. Six months is an example, not a universal threshold. Opens alone are an unreliable basis for the decision.
- Imported contacts: check origin, permission and existing opt-outs before enrollment. An address verification result does not establish permission to send.
- Reactivation: define who can approve it and which evidence is needed. Keep imports and integrations from silently undoing suppression.
These controls belong alongside your subscription and preference model. Give the marketing owner a view of excluded records and the reason for exclusion, so a smaller audience is understood rather than overridden.
Choose sending infrastructure around the actual pattern
A dedicated IP is not an automatic improvement. Assess sending consistency, expected volume, monitoring capacity and HubSpot’s current prerequisites before making that decision. Agree a warm-up plan appropriate to the account instead of promising a fixed number of weeks.
Separating marketing and operational sending streams can make ownership and troubleshooting clearer. It does not guarantee that reputation issues are fully isolated. Record the domains, senders and teams responsible for each stream.
Leave the team with an operating checklist
The useful handover is a short list of checks and named owners: authentication status, complaint trends, bounce reasons, suppression rules, unsubscribe tests and a response when a threshold is crossed. Review it after a campaign incident or an infrastructure change.
Before approving the next send, the operator should be able to explain who will receive it, why they qualify, how they can stop it and what signal would make the team pause. That is a stronger foundation than optimizing subject lines against an audience nobody has reviewed.
Trace the configuration behind delivery problems.
I review authentication, suppression, preference capture and campaign practices, then prioritize the changes your team can implement.
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