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If your test emails show a missing thumbnail or land in spam, the usual cause is your domain’s reputation. Domain reputation measures how trustworthy your domain looks to email providers, and it directly affects deliverability. Use a free tool like MXToolbox, EasyDMARC, or MultiRBL to check whether your SPF, DMARC, and DKIM records are set up correctly.

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Key takeaways

  • A missing email thumbnail or emails going to spam is usually a signal to review your domain’s reputation.
  • Domain reputation reflects how trustworthy your domain appears to email providers and impacts email deliverability, SEO, and overall credibility.
  • Three free tools can check it: MXToolbox, EasyDMARC, and MultiRBL.
  • These tools show whether SPF, DMARC, or DKIM records are missing, confirm your SSL certificate status, and reveal whether your domain is on any anti-spam blacklist.
Did you test your email and it looks like this? Spam-flagged email with broken video thumbnail showing only alt text link If that is the case, it’s time to review your Domain’s reputation. A domain’s reputation is a measure of how trustworthy and credible domains appear to email providers, search engines, or other platforms. It impacts email deliverability, SEO rankings, and overall digital credibility. How do we test this? There are several free tools online that can provide such information.
  1. https://mxtoolbox.com/
MXToolbox SuperTool MX Lookup page with domain name field
  1. https://easydmarc.com/
EasyDMARC Analyze Your Domain Security page with Scan Domain button
  1. https://multirbl.valli.org/
MultiRBL complete IP check for sending mailservers with FCrDNS and DNSBL lookup With these 3 tools, you’ll be able to get valuable information about your Domain reputation. Understand if any of the SPF, DMARC, and DKIM keys are missing. Confirm the status of the SSL certificate and even check if your domain has been added to any blacklist Anty Spam archives. Click here for more in-depth information about deliverability

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Frequently asked questions

A broken thumbnail or spam placement is typically a domain reputation issue. It’s a signal to review how trustworthy your domain looks to email providers, since that directly affects deliverability.
Domain reputation is a measure of how trustworthy and credible your domain appears to email providers, search engines, and other platforms. It impacts email deliverability, SEO rankings, and overall digital credibility.
You can use MXToolbox (mxtoolbox.com), EasyDMARC (easydmarc.com), and MultiRBL (multirbl.valli.org). Together they give you valuable information about your domain’s reputation.
Check whether any of your SPF, DMARC, or DKIM keys are missing, confirm the status of your SSL certificate, and see whether your domain has been added to any anti-spam blacklist.
Updated July 2026.