What This Process Does
A suppression list is a user-created list combined with an automation that allows you to bulk unsubscribe contacts you don't want to communicate with anymore. This is useful when migrating from another email platform or when you need to remove multiple unengaged or problematic contacts at once.
Important billing note: Unsubscribed contacts now count toward your SendX plan limit and you'll be billed for them. To avoid paying for contacts you're not emailing, you'll need to export their data and delete them after unsubscribing (covered in Step 5).
When and Why You'd Use This
You might need to create a suppression list when:
Migrating from another email platform and need to import previously unsubscribed contacts to prevent accidentally emailing them
Cleaning up hard bounces or spam complaints from your previous email service provider
Bulk unsubscribing contacts who haven't engaged with your emails in a long time
Removing purchased or low-quality lists you no longer want to contact
This is a best practice, not a compliance requirement. You're choosing to mark certain contacts as "do not email" to maintain list quality and sender reputation.
Complete Step-by-Step Process
Step 1: Create the Suppression List
Navigate to Audience → Lists in your SendX account
Click Create List
Name your list clearly (e.g., "Suppression List," "Do Not Email," "Unsubscribed Contacts")
The name doesn't trigger any special behavior—it's just for your organization
Choose a name that makes it obvious this list contains contacts you don't want to email
Do not import contacts yet. You must set up the automation first.
Step 2: Create the Unsubscribe Automation
This automation will automatically unsubscribe anyone added to your suppression list.
Go to Automate in the top navigation
Click Create Automation
Set the trigger:
Give the Automation a name
Choose "Subscribed to a List"
Select the suppression list you just created (e.g., "Suppression List")
Note: "Subscribed to a List" means "added to this list by any method" (import, API, manual addition, etc.)
Add the action:
Click Add Action
Choose "Unsubscribe Contact"
This will globally unsubscribe the contact from ALL future campaigns
Activate the automation
Verify it's running before proceeding to Step 3
Why this order matters: If you import contacts before creating the automation, they'll be added to your account as subscribed contacts, potentially exceeding your plan limit and locking your account.
Step 3: Import Your Suppression Contacts
Now you're ready to import contacts who should be unsubscribed.
Import process:
Prepare your CSV file containing contacts to suppress (include at minimum: email addresses)
Go to Audience → Lists
Click on your suppression list
Click Import Contacts
Upload your CSV file
Map the fields correctly
Complete the import
What happens automatically:
Each contact is added to the suppression list
The automation triggers instantly
The contact is marked as globally unsubscribed (cannot receive any campaigns)
SendX will automatically exclude them from all future campaigns
After import completes:
Verify the automation ran by checking a few contacts' status
Step 4: Verify Unsubscribe Status
Click on a few contacts from your suppression list
Check their profile to confirm they show as "Unsubscribed"
Verify the automation executed successfully
⚠️ Step 5: Export and Delete Contacts to Avoid Billing Charges
Critical: Unsubscribed contacts still count toward your plan limit and you'll be billed for them. To avoid paying for contacts you're not emailing, follow these steps:
5A: Export the contact data (for your records)
Go to Audience → Segments
Click Create Segment
Set the segment criteria to include all contacts from your suppression list:
Condition: "Is in list" → Select your suppression list
Save the segment
Export this segment to download a CSV backup of these contacts
Store this file safely in case you need it for compliance or record-keeping
5B: Delete the contacts to remove them from billing
While viewing your newly created segment
Click the checkbox next to the segment name (or use the three-dot menu)
Click Delete
Check the box: "Delete associated contacts?"
Click Delete to confirm
What this accomplishes:
Removes unsubscribed contacts from your account entirely
Reduces your contact count and billing charges
Preserves your suppression list and automation for future imports
You retain a CSV backup for your records
💡 Important Notes and Limitations
Billing: Unsubscribed Contacts Are Still Billed
Unlike some other platforms, SendX counts unsubscribed contacts toward your plan limit
If you keep unsubscribed contacts in your account, you'll pay for them
Always export and delete suppressed contacts after unsubscribing them to avoid charges
Account Locking When Exceeding Plan Limits
If your contact count exceeds your plan tier limit by even 1 contact, your account will be locked
You'll see a notification asking you to delete excess contacts or upgrade your plan
This is why coordinating with Support for large imports is critical
Contacts That Should Go in Your Suppression List
✅ Include these:
Unsubscribed contacts from your previous email platform
Hard bounces (permanent email delivery failures)
Spam complaints
Contacts who explicitly requested to be removed from your list
Long-term unengaged contacts you've decided to stop emailing
❌ Don't include these:
Soft bounces (temporary delivery issues—these might resolve)
Currently engaged, active contacts
Contacts you might want to re-engage in the future (consider segmenting them separately instead)
Duplicate Contacts
SendX automatically handles duplicates—if the same email is imported multiple times, it's only counted once
Don't worry about accidentally importing duplicates
The Automation Runs Forever
Once set up, this automation continues working for all future imports
Any contact added to this list in the future (via import, API, or manual addition) will automatically be unsubscribed
You don't need to recreate the automation each time
Common Questions and Troubleshooting
Q: What happens if someone on my suppression list tries to re-subscribe?
A: It depends on how they re-subscribe:
Via a form on your website: They will be automatically re-subscribed. SendX allows contacts to opt back in if they actively submit a form.
Added to another list manually or via API: They will remain unsubscribed. You'd need to manually re-subscribe them in SendX or create a separate re-subscription automation.
Imported to the suppression list again accidentally: They'll remain unsubscribed (no change).
The suppression list automation does not prevent someone from opting back in through a form—it only unsubscribes people when they're added to that specific list.
Q: My account got locked during import. What do I do?
A:
Contact SendX Support immediately via live chat or email
Explain you're importing to a suppression list with an automation set up
Support can help unlock your account
In the future, notify Support before starting large imports to prevent this
The lock happens because your contact count temporarily exceeds your plan limit during import. Support can assist with resolving this quickly.
Q: Can I skip the export and delete step (Step 5)?
A: You can, but you'll be paying for contacts you're not allowed to email.
Example: If you have a 10,000-contact plan and import 2,000 suppression contacts:
Without deletion: You're now paying for 12,000 contacts (and need to upgrade)
With deletion: You're back to 10,000 contacts (your original plan remains sufficient)
Unless you have a compliance reason to keep unsubscribed contacts in SendX, it's financially beneficial to remove them.
Q: Why not just import and manually unsubscribe each contact?
A: You could, but:
Manually unsubscribing thousands of contacts is extremely time-consuming
The automation handles this instantly for any volume
You can reuse this automation for future imports without any additional work
It's less error-prone than manual processes
Q: What if I accidentally send a campaign to my suppression list?
A: SendX will automatically prevent this:
Unsubscribed contacts never receive campaigns, even if you target the list they're on
As long as your automation successfully unsubscribed them, they're globally excluded from all email sends
Double-check that contacts show "Unsubscribed" status in their profiles to confirm
Q: Will this affect my email deliverability or sender reputation?
A: Positively, yes:
Removing unengaged contacts, bounces, and spam complaints improves your sender reputation
Cleaner lists lead to better open rates, click rates, and inbox placement
Email providers (Gmail, Outlook, etc.) reward senders who maintain quality lists
Q: Can I use this for GDPR or CAN-SPAM compliance?
A: This process helps with best practices, but:
CAN-SPAM: You must honor unsubscribe requests within 10 business days. This automation accomplishes that instantly.
GDPR: This helps you avoid emailing people who've withdrawn consent. However, GDPR also requires you to delete personal data upon request—so the "export and delete" step (Step 5) aligns with this.
Not a compliance feature: This is a workflow you create, not a built-in compliance tool. Always consult legal guidance for compliance requirements.
Q: What's the difference between unsubscribing and deleting contacts?
A: Important distinction:
Action | Contact Status | Billing Impact | Can Re-subscribe? |
Unsubscribe | Marked "unsubscribed" in SendX | Still counts toward your plan limit (you're billed) | Yes, manually or via form |
Delete | Completely removed from SendX | Does not count toward your plan limit (not billed) | Only if re-imported or added again |
For suppression lists, you typically want to do both: unsubscribe first (for compliance/safety), then delete (to save money).
Q: I need to reuse contacts I previously suppressed. How do I re-import them?
A:
Use the CSV file you exported in Step 5A
Import them to a different list (not the suppression list!)
Manually re-subscribe them in SendX, or create a re-subscription automation
Warning: Only re-import contacts who have given you explicit permission to email them again. Re-subscribing people without consent violates email marketing laws and damages your sender reputation.
Quick Reference Checklist
Use this checklist to ensure you complete the process correctly:
[ ] Create a suppression list with a clear name
[ ] Create automation: Trigger = "Subscribed to a List" (your suppression list), Action = "Unsubscribe Contact"
[ ] Activate and verify the automation is running
[ ] (For large imports) Contact SendX Support before importing
[ ] Import your suppression contacts to the list
[ ] (After import) Notify SendX Support that import is complete
[ ] Verify contacts show as "Unsubscribed" in their profiles
[ ] Create a segment of all contacts in the suppression list
[ ] Export the segment to save a CSV backup
[ ] Delete the segment with the "Delete associated contacts" option checked
[ ] Verify your contact count has decreased and you're within your plan limit
Need Help?
If you encounter any issues during this process or have questions about:
Account locking during imports
Re-subscribing previously suppressed contacts
Billing questions related to unsubscribed contacts
Setting up the automation correctly
Contact SendX Support immediately via live chat or email for personalized assistance.
Pro Tip: Set a calendar reminder to review and clean your suppression list quarterly. Export any newly unsubscribed or bounced contacts, then delete them to keep your billing costs optimized.