Emails Not Delivering
Troubleshoot dunning emails that are not reaching your customers, including spam filtering, bounces, and domain verification issues.
If your dunning campaign emails are being sent by LostChurn but customers are not receiving them, the issue is usually related to spam filtering, domain authentication, or invalid email addresses.
Symptoms
- Campaign emails show Sent status in the delivery log but customers report not receiving them
- High bounce rate visible in Campaigns > Delivery Stats
- Emails landing in customers' spam or junk folders
- Delivery log shows Bounced or Rejected status for specific addresses
- Open rate is significantly lower than expected (below 10%)
Common Causes
- Spam filters blocking delivery -- the sending domain lacks proper authentication records, causing spam filters to reject or quarantine the emails
- Sending domain not verified -- SPF, DKIM, or DMARC DNS records have not been configured for your custom sending domain
- Invalid or inactive email addresses -- the customer email on file is misspelled, no longer active, or belongs to a disposable email provider
- Email address on the bounce list -- a previous hard bounce caused the address to be suppressed, and subsequent sends are blocked automatically
- Custom sending domain DNS propagation -- DNS records were recently added but have not fully propagated yet
Step-by-Step Fix
1. Check the delivery log
Navigate to Campaigns > Delivery Logs and filter by the campaign or customer in question. Look at the Status column for each email:
| Status | Meaning | Action |
|---|---|---|
| Delivered | Email accepted by the recipient's mail server | Check spam folder with the customer |
| Bounced | Recipient mail server permanently rejected the email | Verify the email address is correct |
| Soft Bounced | Temporary delivery failure (mailbox full, server down) | LostChurn will retry automatically |
| Rejected | Sending provider blocked the email before delivery | Check domain verification |
| Spam Complaint | Recipient marked the email as spam | Review email content and frequency |
2. Verify domain DNS records
If you are using a custom sending domain (e.g., recovery@yourdomain.com), check your domain verification status in Settings > Email > Custom Domain.
LostChurn uses CNAME-based delegation through Resend, which automatically handles SPF and DKIM signing. You need three CNAME records pointing to Resend's infrastructure -- the exact values are shown in your dashboard.
Common DNS issues:
- Records not added -- copy all three CNAME records from Settings > Email > Custom Domain and add them to your DNS provider
- Incorrect record values -- record names and values must match exactly as shown in the dashboard
- Propagation delay -- DNS changes can take up to 48 hours, though most propagate within 1-2 hours
Use a tool like MXToolbox to verify that your CNAME records have propagated. After adding the records, click Verify DNS in the dashboard to trigger a recheck.
If your domain status shows Warming Up, note that new domains start with a daily sending limit that ramps from 50 to 5,000 emails over 22 days. During warmup, overflow emails are sent from the default LostChurn sender. See Domain Warmup for details.
We also recommend adding a DMARC record for your domain:
_dmarc.yourdomain.com TXT "v=DMARC1; p=none; rua=mailto:dmarc-reports@yourdomain.com"3. Check the bounce list
LostChurn automatically suppresses email addresses that have previously hard bounced to protect your sender reputation. To check if a specific address is suppressed:
- Go to Settings > Email > Bounce List
- Search for the customer's email address
- If the address appears, you can remove it if you believe the issue has been resolved (for example, the customer fixed their mailbox). Click the address and select Remove from bounce list.
Repeatedly sending to an address that hard bounces will damage your sender reputation and may cause your entire domain to be blocked. Only remove addresses from the bounce list if you have confirmed the issue is resolved.
4. Verify the customer's email address
Check the email address on the payment record or customer profile. Common issues include:
- Typos in the domain (e.g.,
@gmial.cominstead of@gmail.com) - Addresses from disposable email services that have expired
- Work email addresses where the employee has left the company
If the email is incorrect, update it in your payment processor. LostChurn will pick up the change on the next sync.
5. Test email delivery
Send a test email from the campaign editor to verify delivery is working:
- Go to Campaigns and select the campaign
- Click Send Test Email
- Enter your own email address and click Send
- Check your inbox (and spam folder) for the test email
If the test email arrives, delivery infrastructure is working correctly and the issue is specific to the recipient's mail server or address.
Still Not Working?
If emails are still not being delivered after completing the steps above:
- Check status.lostchurn.com for any incidents affecting email delivery.
- If you are using a custom sending domain, try temporarily switching to the default LostChurn sending address (Settings > Email > Sending Address) to determine whether the issue is domain-specific.
- Contact support at support@lostchurn.com with the campaign name, affected customer email addresses, and screenshots from the delivery log.