What are the best tools for troubleshooting deliverability?
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Your placement is tanking and you need answers fast. The challenge isn't finding tools. it's knowing which one to pull out first and what you're actually diagnosing.
Start with your mailbox provider's dashboard. Gmail Postmaster Tools (free) shows you Gmail's view of your domain reputation, spam rate, and authentication pass rates. For Microsoft Outlook, SNDS (the Sender Network Data Service) is free but requires setup. These tell you what the big mailbox providers think of you. Check them daily during recovery. Screenshot trends weekly so you can see if you're actually improving.
Then move to reputation and blocklist checks. MXToolbox and HetrixTools let you see if you're on any blocklists and validate your DNS and authentication records (SPF, DKIM, DMARC). If you're blocked somewhere, these tools are how you find out and prove you've fixed it. Spamhaus is the most relevant for most senders.
The order matters. Check Postmaster Tools first. If you're seeing reputation damage, use MXToolbox to verify your authentication records are solid and you're not on blocklists. Different tools measure different problems. don't tool-hop without a reason.
Authentication basics and blocklist monitoring are your next reads. Once you've diagnosed the problem with these free tools, you'll know whether you need deeper help. Consider Review My Emails SOS for a personalized diagnosis if you're stuck.
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