How To Manage Exclusions
In this guide, you'll learn what exclusions are, how to add them manually, how to sync them automatically through integrations, and how to copy them across workspaces, so warm-up emails and noise never pollute your inbox.
What are Exclusions?
Exclusions help you filter out warm-up, noise, or irrelevant emails from your inbox. By adding exclusion keywords or codes, MasterInbox ensures these emails don’t clutter your workspace and only relevant conversations surface.
Warm-up emails are automatically generated messages used to build sender reputation. They're not real prospect replies, but without exclusions, they land in your inbox alongside real conversations and create noise that can trigger automations, pollute filters, and confuse your team.
Without Exclusions Warm-up emails and noise appear alongside real replies. Filters and automations fire on irrelevant messages. Your inbox becomes unreliable.
With Exclusions Warm-up codes and noise tags are filtered out automatically. Only real prospect replies appear in your inbox. Filters and automations work correctly.
How Exclusions Work
MasterInbox uses exclusion rules (keywords, tags, or codes) to automatically filter incoming emails.
You can manage exclusions in two ways:
Manual setup (Settings → Exclusions)
Automatic sync via integrations (SmartLead, Instantly, Emailbison, etc.)
Add Exclusions Manually
Go to Settings and click on Exclusions.
Here you can:
Add warm-up phrases, keywords, or exclusion codes
Paste multiple entries at once
Edit or remove existing exclusions
Paste or type down your exclusion codes or keywords into the exclusions field.
Save your changes.
Exclusion Matching Options
MasterInbox provides additional matching options to give you more control over how exclusion tags are detected.
Apply on Replies Message Only
When enabled, exclusion rules are applied only to reply emails. New incoming conversations that are not replies will not be checked against your exclusion tags.
Recommended use case: Enable this if you only want to filter warm-up replies while allowing other incoming emails to be processed normally.
Enable Auto Tag Detection
Enable Auto Tag Detection to allow MasterInbox to automatically identify and filter warm-up emails using its built-in warm-up detection system.
This reduces the need to manually add every warm-up code or exclusion tag, helping keep your inbox clean with minimal configuration.
Recommended use case: Leave this enabled to automatically detect common warm-up emails without maintaining a manual exclusion list.
Enable Includes Match
Enable Includes Match to perform partial matching when checking exclusion tags.
Instead of requiring an exact match, MasterInbox will exclude emails whenever an exclusion keyword or code appears anywhere within the subject or message.
Example:
If your exclusion tag is warmup, emails containing subjects such as "Weekly warmup report" or "abc_warmup_xyz" will also be excluded.
Recommended use case: Enable this when exclusion keywords or warm-up codes appear as part of a longer string rather than as an exact value.
Check your outreach tool's settings or documentation to find the exact warm-up codes or tags it uses. These are usually a string of random characters or letters attached to warm-up email subjects, copy them exactly as they appear.
Copying Exclusions to Another Workspace
If you manage multiple workspaces, you can copy your exclusion list across without rebuilding it manually.
Go to Settings → Exclusions.
Click Copy to Workspaces. A page will open showing your available workspaces.
Select the workspaces you want to copy the exclusions to.
Confirm. The exclusions transfer instantly
When copying exclusions:
The destination workspace does not replace existing rules
Instead, it merges with existing exclusions
Merging exclusions may result in duplicate or overlapping rules. Review workspace settings after copying.
MasterInbox allows you to block specific email addresses and entire sender domains and prevent duplicate forwarded emails from appearing in your workspace.
These settings help keep your inbox clean by filtering unwanted conversations before they reach your team.
Email Forwarding Blocklist
The email forwarding blocklist allows you to prevent emails from specific senders from being forwarded into MasterInbox.
How to Add an Email
Go to Settings → Exclusions.
Locate Email Forwarding Blocklist.
Enter the email address you want to block.
Click Add.
Save your changes.
Apply on Sent Messages
Enable Apply on Sent Messages if you also want the blocklist to apply to forwarded emails that originate from sent messages.
When enabled, blocked email addresses are filtered regardless of whether the forwarded message originated from an incoming or sent conversation.
Common Use Cases
Prevent internal company emails from being forwarded.
Exclude automated system notifications.
Ignore forwarding from specific senders.
Reduce unnecessary conversations in your workspace.
Domain Blocklist
The Domain Blocklist allows you to block all emails from a specific sender domain.
Instead of blocking individual email addresses, you can block every sender using the same domain.
How to Add a Domain
Go to Settings → Exclusions.
Locate Domain Blocklist.
Enter the domain you want to block (for example, example.com).
Click Add.
Save your changes.
Once added, emails from any address using that domain will be excluded from your inbox.
Common Use Cases
Block internal company domains.
Exclude partner or vendor notifications.
Prevent automated system emails from specific domains.
Keep testing or staging domains out of your production workspace.
Dedupe Forwarded Emails from Threads
Enable Dedupe Forwarded Emails from Threads to prevent duplicate forwarded messages from creating multiple conversations inside MasterInbox.
When enabled, MasterInbox detects forwarded emails that belong to the same conversation thread and keeps only a single conversation.
Syncing Exclusions via Integration
When integrating an outreach tool like Smartlead or Instantly, you'll see a Sync Exclusion toggle during the integration setup.
Go to Settings → Integrations.
Select your outreach tool (e.g. Smartlead) and enter your API key
Locate the Sync Exclusion toggle.
Turn it ON.
Save. Exclusion tags from your outreach tool will sync into Master Inbox automatically.
Once Sync Exclusion is enabled, any exclusion tags configured in your outreach tool will carry over into Master Inbox automatically, keeping both platforms aligned without manual entry.
Common Use Cases
Prevent duplicate conversations when multiple team members forward the same email.
Keep forwarded inboxes organized.
Reduce duplicate notifications.
Improve conversation management for shared inboxes.