This guide explains why lemwarm gets paused, what each error means, what typically causes it, and the exact steps you can take to fix the issue and safely restart warming.
Overview of Lemwarm Pauses
Lemwarm pauses occur when certain conditions disrupt the email warm-up process. These conditions can include:
SPF record verification failures
Use of third-party relay services
DNS propagation delays
Configuration issues
External factors, such as email provider incidents
1. DMARC-related pause reasons
ERR_SETUP_10011 – valid DMARC, but your server rejects the email
What it means
Your domain does have a valid DMARC record, but your email server is rejecting lemwarm emails due to a DMARC-related misconfiguration.
What causes it
Your ESP (email service provider) is incorrectly rejecting emails that should pass authentication.
How to fix it
Check your DMARC record in DNS.
If DMARC is valid, contact your ESP and tell them they are rejecting emails for a DMARC reason that should not fail.
After they fix the configuration, restart lemwarm.
ERR_SETUP_10006 – invalid DMARC
What it means
Your DMARC record is invalid and recipients are rejecting your emails.
What causes it
DMARC is set too strictly or incorrectly.
How to fix it
Review your DMARC record formatting carefully.
Avoid strict policies such as
p=rejecttoo early.Use lemlist’s DNS setup guide: https://www.lemwarm.com/dns-setup
Update the record, wait for propagation, then restart lemwarm.
Note: DNS changes, such as updates to your DMARC record, can take up to 72 hours to propagate fully. Use an online DNS checker to verify the changes have taken effect.
2. Low reputation pause reasons
ERR_REP_10001 / ERR_REP_10002 – low sender reputation
What it means
Your sending reputation is too low, and recipients reject your emails before they reach the inbox.
What causes it
Too many recent bounces
Sending too fast
Domain is new or cold
Poor list quality
How to fix it
Reduce sending volume.
Remove invalid or risky leads from campaigns.
Continue warming gradually.
If the domain reputation is severely damaged, consider using a new domain for outreach.
3. Antispam-related pause reasons
ERR_REP_10003 – rejected as spam
What it means
Recipient spam filters rejected several lemwarm emails.
What causes it
Spam filters like Zoho MailPolicy, ivmURI blocklists, or general spam detection
Your ESP marking lemwarm traffic as spam
Temporary provider issues
Restrictions on sending to external domains
How to fix it
Do a DNS check for your domain.
Contact your ESP and ask why they flagged the message as spam.
Confirm they allow sending and receiving from external domains.
Restart lemwarm once the issue is resolved.
ERR_SETUP_10001 – receiver marks too many lemwarm emails as spam
What it means
Your own inbox spam filter is rejecting incoming warming emails.
How to fix it
Check your spam filtering software.
Review SPF, DMARC, and DNS with your provider.
Allow lemwarm traffic and restart.
ERR_SETUP_10003 – mailchannels incompatibility
What it means Lemwarm pauses when emails are routed through third-party relay services like mailchannels.net, as these services can flag lemwarm emails as spam. This ensures the integrity of the warm-up process.
How to fix it
Disable mailchannels or switch to an ESP that doesn’t use it.
Restart Lemwarm after disabling the third-party relay service to resume the warm-up process.
4. Forwarding issues
ERR_SETUP_10002 – external forwarding not allowed
Your ESP blocks automatic forwarding rules.
Some email servers may return errors like "550 5.7.520 Access denied" when Lemwarm attempts to send emails through forwarded accounts.
Fix
Contact your administrator to adjust forwarding permissions.
ERR_SETUP_10016 – forwarding blocked by transport rule
Your provider uses rules that block forwarded messages during lemwarm exchanges.
Fix
Ask IT to review filtering rules.
5. Rejections due to provider policies
ERR_SETUP_10004 / ERR_REP_10007 / ERR_REP_10008 / ERR_REP_10009 – provider rejects messages
These errors mean your provider has rules or filters blocking outgoing or incoming lemwarm emails.
Common reasons:
“Blocked permanently due to successive mailings”
Blacklisted domain
Transport rule violations
Banned IP
Fix
Review filtering rules with your ESP.
Confirm your domain is not blacklisted.
Check your DNS (MX, SPF, DMARC).
Remove strict internal rules that block lemwarm.
6. Authentication issues (SPF, DKIM, DMARC)
ERR_SETUP_10005 – sender cannot be authenticated
DKIM, SPF or DMARC is missing and recipients are rejecting emails.
ERR_SETUP_10007 – receiver SPF fail
Receiver's SPF record is misconfigured.
ERR_SETUP_10008 – sender SPF fail
Your SPF setup is wrong or incomplete.
ERR_SETUP_10009 – DKIM or SPF fail
Your domain fails DKIM or SPF checks.
ERR_SETUP_10010 – MX, SPF, DMARC errors
Your emails are rejected because the provider cannot verify authentication.
Fix for all authentication errors
Validate SPF, DKIM, DMARC in DNS.
Confirm records point to the correct sending servers.
Avoid duplicates or multiple SPF TXT entries.
Fix any formatting issues and wait for propagation.
7. DNS or MX problems
ERR_SETUP_10013 / ERR_SETUP_10014 – DNS misconfigured
DNS record missing, incorrect, or unreachable.
ERR_SETUP_10015 – MX record not found
Your domain has no valid MX record.
How to fix it:
Check DNS zone for typos or missing records.
Add/repair MX, SPF, DMARC.
Ensure your domain resolves correctly.
Note: DNS changes may take up to 72 hours to propagate. Use online tools to monitor the propagation status.
8. Provider unreachable or expired
ERR_PROV_10004 / ERR_PROV_10005 / ERR_PROV_10007
These errors indicate your provider was temporarily unreachable, blocked, or expired.
How to fix it
Check your provider’s service status.
Validate MX record.
Retry after the provider resolves the outage.
9. Full mailbox
ERR_PROV_10006 – mailbox over quota
Your inbox is full or restricted by policy.
Fix
Delete old emails.
Increase mailbox storage.
Restart lemwarm.
10. Mailbox does not exist
ERR_PROV_10002 / ERR_PROV_10003 – account invalid
Your mailbox no longer exists or is misconfigured.
This can also occur if the mailbox is newly created and not fully configured.
Fix
Check if the mailbox is active.
Review forwarding rules.
Confirm the domain exists and resolves.
11. Unknown bounces
ERR_10000 – unknown error
Bounce did not match any known error pattern. After 3 occurrences, lemwarm pauses.
Fix
Review DNS, mailbox configuration, and provider rules.
12. Blacklists
ERR_REP_10005 – listed on SpamRL
ERR_REP_10006 – listed on SpamCop
Your domain appears on a public spam blacklist. Factors contributing to blacklisting can include a domain's history of malicious activity, misconfigured email authentication records, inadvertent interactions with spam traps, or the reputation of the shared IP used by the email service provider. HoneyDB and IPsum, unlike traditional spam blacklists, are threat-intelligence feeds that focus on IP reputation rather than domain reputation. Listings on these feeds often result from automated activity or issues with shared servers. Different blacklist tools may show varying results due to differences in their databases and criteria. For instance, MXToolbox aggregates many sources, including minor lists, while lemlist focuses on major, impactful lists. This discrepancy does not necessarily indicate a real-world deliverability issue. Additionally, inherited IP reputation can play a role, especially when purchasing a new domain with associated IPs that may already have a negative reputation. Shared infrastructure, such as using shared IPs through platforms like lemlist, can also affect your domain’s reputation due to the actions of other users sharing the same IP.
Fix
Request delisting on the blacklist website.
Warm up a secondary domain meanwhile.3. Use the Lemwarm blacklist check feature to monitor and verify the domain's blacklist status.
Audit and rectify domain configurations like SPF, DKIM, and MX records to improve email authentication.
Pause email campaigns temporarily to prevent further damage to your reputation while resolving blacklist issues.
Use external tools like MXToolbox or MultiRBL to verify blacklist status and identify the source of the issue.
For HoneyDB, submit a delisting request via their contact form, providing evidence that your IP did not engage in malicious activity.
For IPsum, submit a delisting request on their GitHub repository, including the IP address, an explanation of the listing error, and supporting details like reverse DNS and logs. 8. Contact your domain provider to request information about the blacklist and ask them to clean up any reputation issues tied to their IPs or infrastructure. 9. Follow the specific delisting process of the blacklist provider, which typically involves submitting required information and waiting for a review process that can take 24–72 hours. For example, Barracuda provides a Removal Request Form.
13. lemwarm toggle check
ERR_PROV_10017 – DNS errors detected by lemwarm toggle
lemwarm auto-paused because DNS (MX, SPF, DMARC, or CTD) is not valid.
Fix
Double-check all DNS records before restarting.
FAQs
Should Lemlist Be Included in My SPF Record?
No, you should not include Lemlist in your SPF record because Lemlist does not send mail directly. Your actual email provider (e.g., Google, Outlook, Zoho) sends on your behalf. Example SPF format:
v=spf1 include:spf.protection.outlook.com ~all
Where Can I See Why Lemwarm Was Paused?
Check the notifications section of your Lemwarm dashboard. It provides details on the reason for any automatic pause, such as rejected deliveries due to anti-spam filtering.