Bounce Monitoring Workflow

Protect your email sender reputation with automated bounce detection and suppression. This workflow catches bounces as they happen rather than waiting for periodic cleanup.

How It Works

Condition	Action
Hard bounce detected	Alert admin immediately, suppress contact
Suppression threshold reached (commonly 2-3 bounces)	Auto-suppress from marketing emails
Review threshold reached (commonly 3-5 bounces)	Flag for weekly manual review (delete vs. recover)

Prerequisites

HubSpot Marketing Professional or Enterprise plan
A custom contact property (e.g., email_health_flag or delivery_status) — checkbox or dropdown with value: "flagged for review"
Admin email or Slack channel for hard bounce alerts

Building the Workflow: Three Options

Option 1: Manual UI Build

Follow the step-by-step instructions in the "Execute" section below. This is the most reliable method and gives you full control over every trigger, branch, and action.

Option 2: HubSpot Breeze AI

HubSpot's built-in Breeze AI can generate a workflow skeleton from a natural language prompt. Navigate to Automation > Workflows > Create workflow > "Describe what you want" and paste the following prompt:

Create a contact-based workflow that triggers when the "Email Bounce" property
is known (has a value). The workflow should:

1. First, check if the contact has a hard bounce reason (hard_bounce_reason is known):
   - If YES: send an internal notification saying "Hard bounce: [email]" and set the
     contact as a non-marketing contact
   - If NO: continue to the next check

2. Check if the bounce count is greater than or equal to [your suppression threshold, commonly 2-3]:
   - If YES: set the contact as a non-marketing contact, then check if bounce count
     is >= [your review threshold, commonly 3-5]. If so, set a custom property
     "[your bounce review property]" to "flagged" and send an internal notification
     saying "Contact [email] has [review threshold]+ bounces - review for deletion"
   - If NO: end (below threshold, monitor only)

Enable re-enrollment so the contact re-enters if their bounce count increases.

CRITICAL WARNING: Breeze trigger limitations. Breeze creates event-based triggers (OR logic) instead of filter-based triggers (AND logic). After Breeze creates the workflow, you MUST manually verify and fix the trigger/enrollment conditions in the UI. Breeze is best used for creating the workflow skeleton (actions, branches, delays) -- the trigger conditions almost always need manual correction.

Additional Breeze limitations for this workflow:

Breeze cannot create "is unknown" branch conditions -- you must verify that branch conditions checking for hard bounce reason are correctly configured
Breeze cannot configure re-enrollment rules -- you must enable re-enrollment manually
Breeze may flatten the nested branch structure (hard bounce check > 2+ bounces > 3+ bounces) into a single level

Option 3: Claude Anthropic Chrome Extension

The Claude Anthropic Chrome extension lets Claude see and interact with the HubSpot workflow builder UI directly. You can describe the workflow logic in natural language and Claude will click through the UI to build it. This is often more accurate than Breeze for workflows with nested branching logic (this workflow has three levels of branches), because Claude can verify the branch hierarchy visually.

To use this approach:

Open the HubSpot workflow builder in Chrome (Automation > Workflows > Create workflow)
Activate the Claude Chrome extension
Describe the workflow using the design table and instructions from this skill

Note on Fast Mode: If you're using Claude Code's Fast Mode to speed up workflow creation, be aware of the billing model: Haiku usage is included in your subscription, but Opus in Fast Mode consumes extra credits. For workflow building tasks (which are UI-heavy and may require many interactions), consider whether the speed tradeoff is worth the credit cost.

Step-by-Step Build Instructions

Stage 1: Before — Create Properties

Create your bounce review property (e.g., email_health_flag or delivery_status):
- Object: Contact
- Type: Single checkbox or dropdown
- Group: Contact information
Identify your current bounce baseline — run a quick search for contacts where hs_email_bounce > 0 to understand the starting volume.

Stage 2: Execute — Build the Workflow

Build a single contact-based workflow with branching logic.

Trigger: hs_email_bounce is known (fires when bounce count updates)
Branch 1: Hard bounce check
- Condition: hs_email_hard_bounce_reason_enum is known
- YES:
  - Send internal notification: "Hard bounce: {email} — {hs_email_hard_bounce_reason_enum}"
  - Set hs_marketable_status to non-marketing (workflow action)
- NO: Continue to Branch 2
Branch 2: Bounce count >= your suppression threshold (commonly 2-3)
- Condition: hs_email_bounce is greater than or equal to your suppression threshold
- YES:
  - Set hs_marketable_status to non-marketing (workflow action)
  - Continue to Branch 3
- NO: No action (below threshold — monitor only)
Branch 3: Bounce count >= your review threshold (commonly 3-5)
- Condition: hs_email_bounce is greater than or equal to your review threshold
- YES:
  - Set your bounce review property = flagged
  - Send internal notification: "Contact {email} has [review threshold]+ bounces — review for deletion"
- NO: No further action
Settings:
- Re-enrollment: ON (contact should re-enter if bounce count increases)
- Goal: None
Turn on the workflow.

Stage 3: After — Verify

Check workflow history after the first week of email sends.
Review the flagged contacts list weekly — decide for each contact:
- Delete if the email is clearly invalid (typo domain, defunct company)
- Attempt recovery if the domain is valid (could be a temporary mailbox issue)
Monitor overall bounce rate in HubSpot email health dashboard.

Stage 4: Rollback

Turn off the workflow.
Contacts already suppressed remain non-marketing. To reverse:
- Filter contacts suppressed by this workflow (check your bounce review property or workflow history)
- Manually set back to marketing contacts in the UI
Clear your bounce review property values in bulk if needed.

Weekly Review Process

For contacts flagged at your review threshold:

Export the flagged contacts list.
For each contact, check:
- Is the email domain still active? (Quick MX record check)
- Is this a known customer or high-value contact?
- Was the bounce recent or historical?
Delete contacts with invalid domains or clearly fake emails.
Keep suppressed contacts with valid domains but repeated soft bounces.
Clear the bounce review property after review.

bounce-monitoring-workflow