Summary
To resolve blocked CRM emails after importing an old lead list, several steps are recommended. Immediately halt sending to the problematic list and analyze bounce reports and SMTP logs for error messages. Engage with your ESP to open tickets with ISPs/MBPs if applicable. Check sender reputation and comply with email provider policies (Microsoft, Google). Warm up IP addresses gradually, and implement SPF, DKIM, and DMARC authentication. Clean the email list by removing inactive addresses, segmenting it, and re-engaging contacts. Establish feedback loops, regularly check sender reputation, and gain clear consent. Ensure spam filters are tested, and a double opt-in process is used. Old lists should never be imported without cleaning and permission. Monitor domain-specific open rates, and implement tighter controls on who can upload lists. Lastly, ensure valuable content and remove unengaged contacts regularly.
Key findings
- Pause & Analyze: Immediately stop sending to the problem list and analyze bounce reports and SMTP logs.
- ESP Engagement: Engage your ESP to open tickets with ISPs/MBPs if experiencing blocks.
- Sender Reputation & Compliance: Check and maintain a positive sender reputation, and comply with email provider policies.
- IP Warmup & Authentication: Gradually warm up IP addresses and implement SPF, DKIM, and DMARC authentication.
- List Cleaning & Re-Engagement: Clean the email list, segment it, and attempt a re-engagement campaign.
- Feedback Loops & Consent: Establish feedback loops, regularly check sender reputation, and gain clear consent before emailing.
- Spam Filter Testing: Ensure spam filters are tested, and a double opt-in process is used for new subscribers.
- Careful Importing: Avoid importing old lists without proper cleaning and permission.
Key considerations
- Domain Open Rates: Monitor open rates by domain to identify issues with specific providers.
- Upload Controls: Implement tighter controls on who can upload lists to prevent future issues.
- Valuable Content: Focus on providing valuable content to subscribers to increase engagement.
- Unengaged Removal: Remove unengaged contacts regularly to improve sender reputation.
- List Hygiene: Clean the list by segmenting and purging outdated addresses.
- Permission Validation: Validate permission even for previously valid email addresses to ensure ongoing consent and relevance.
What email marketers say
12 marketer opinions
After importing an old lead list into a CRM, blocked emails are a common issue. Several key steps can mitigate this. First, immediately stop sending to the problematic list. Analyze bounce reports and SMTP logs for error messages and bounce codes to diagnose the cause. Implement proper email authentication (SPF, DKIM, DMARC) and regularly check sender reputation. Clean the email list by removing inactive or invalid addresses, segmenting it for targeted campaigns, and considering a re-engagement campaign. A double opt-in process for new subscribers can improve list quality. Avoid importing old lists without proper cleaning and consent, and test emails to pass spam filter checks before sending. It is also important to contact your ESP for support.
Key opinions
- Immediate Pause: Halt sending to the suspect list to prevent further damage to sender reputation.
- Analyze Reports: Examine bounce reports and SMTP logs for specific error messages and bounce codes.
- Authentication: Implement and maintain proper email authentication protocols (SPF, DKIM, DMARC).
- List Cleaning: Regularly clean the email list by removing inactive and invalid addresses.
- Re-Engagement: Segment lists and attempt a re-engagement campaign before fully removing contacts.
- Sender Reputation: Monitor sender reputation using tools to identify and address issues.
- Consent: Avoid importing old lists without proper cleaning and ensuring consent.
- Testing: Test emails to ensure they pass spam filter checks before sending.
Key considerations
- ESP Support: Contact your ESP (Email Service Provider) to open a ticket and seek assistance with the block.
- Domain Open Rates: Monitor open rates by domain (Gmail, Hotmail, etc.) to identify problem areas.
- Control List Uploads: Implement stricter controls on who can upload lists to prevent future issues.
- Content Value: Focus on providing valuable content to subscribers to improve engagement.
- Unengaged Contacts: Remove unengaged contacts regularly to improve sender reputation.
Marketer view
Email marketer from Reddit shares that NEVER import old lists without proper cleaning and consent. Old lists are a surefire way to get your IP blacklisted. Verify all emails before sending, and consider using a double opt-in process to regain consent.
31 Mar 2025 - Reddit
Marketer view
Email marketer from Sender Score shares that regularly check your sender reputation using tools such as Sender Score or Reputation Authority. A low sender score indicates potential issues with your sending practices that may be causing blocks. Analyze the results and address any identified problems.
6 Apr 2025 - Sender Score
What the experts say
3 expert opinions
Resolving blocked CRM emails after importing an old lead list involves focusing on list hygiene, feedback loops, and clear permission. Cleaning the list by segmenting it and suppressing unengaged subscribers is critical. Verify the age of the list and remove outdated addresses. Establish feedback loops with mailbox providers to identify and promptly remove recipients marking emails as spam. Ensure clear and current permission to email the list, even if addresses were once valid.
Key opinions
- List Cleaning: Segment and suppress unengaged subscribers; purge outdated addresses.
- Feedback Loops: Establish and monitor feedback loops with mailbox providers to identify spam complaints.
- Clear Permission: Ensure current and clear permission to email the list, beyond initial validity.
Key considerations
- Age of List: Assess the age of the list and remove addresses older than a specific period to minimize relevance issues.
- Complaint Management: Actively manage complaints by removing recipients who mark emails as spam.
- Permission Validation: Validate permission even for previously valid email addresses to ensure ongoing consent.
Expert view
Expert from Word to the Wise, Dennis Dayman, explains to establish feedback loops with mailbox providers to manage complaints. Set up and monitor these loops to identify recipients who mark emails as spam and promptly remove them from the mailing list.
11 Aug 2023 - Word to the Wise
Expert view
Expert from Word to the Wise, Laura Atkins, explains that cleaning the list is crucial. Segment the list and suppress unengaged subscribers before sending any campaigns. Verify the age of the list and purge addresses older than a certain period to ensure relevance and minimize spam complaints.
28 Mar 2025 - Word to the Wise
What the documentation says
5 technical articles
Resolving blocked CRM emails after importing an old lead list involves several technical and policy-related steps. Checking sender reputation and complying with email provider policies like Microsoft's is crucial. Warming up new IP addresses with low sending volumes initially, and gradually increasing it while monitoring reputation is essential. Authentication with SPF, DKIM, and DMARC, along with adherence to bulk sender guidelines (e.g., Google's), helps ensure deliverability. Analyzing SMTP bounce codes to identify permanent failures (hard bounces) and addressing those causes promptly is also necessary. Implementing SPF records to authorize mail servers and prevent unauthorized use of the domain for sending spam is a foundational practice.
Key findings
- Sender Reputation: Check and maintain a positive sender reputation, especially with providers like Outlook.com.
- IP Warmup: Warm up new IP addresses gradually with low sending volumes initially.
- Authentication: Implement SPF, DKIM, and DMARC authentication protocols.
- Bulk Sender Guidelines: Adhere to bulk sender guidelines provided by email providers like Gmail.
- Bounce Code Analysis: Analyze SMTP bounce codes and address hard bounces immediately.
- SPF Records: Implement SPF records to authorize sending mail servers.
Key considerations
- Microsoft Policies: Ensure compliance with Microsoft's sending policies.
- JMRP: Utilize Junk Email Reporting Program (JMRP) to understand spam markings.
- Engagement Metrics: Monitor engagement metrics during IP warm-up to maintain positive reputation.
- Unsubscribe Process: Make it easy for recipients to unsubscribe to reduce spam complaints.
- Hard Bounce Resolution: Promptly address the causes of hard bounces to prevent further reputational damage.
Technical article
Documentation from SendGrid explains that warming up your IP address is important. When starting with a new IP, start with low volumes and gradually increase the amount of email sent. Monitor your reputation and engagement metrics to ensure you maintain positive sender reputation.
24 Oct 2023 - SendGrid
Technical article
Documentation from SparkPost explains that understand and analyze the SMTP bounce codes. Certain codes indicate permanent failures (hard bounces), while others might be temporary. Address the causes of hard bounces immediately to prevent further damage to your sender reputation.
29 Apr 2022 - SparkPost
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