Free tool
IP Reputation Checker
Enter a sending IP address and we'll look up its reverse DNS (PTR) and check it against common blacklists — two signals that shape how your mail is treated.
How it works
- 1Enter the IPv4 address you send from.
- 2We resolve its reverse DNS and query blacklists.
- 3See whether the IP looks reputable to receivers.
Questions
Frequently asked
Why does reverse DNS (PTR) matter?
Mailbox providers expect a sending IP to have a matching PTR record. A missing or generic PTR is a common reason mail gets filtered.
What's a good IP reputation?
A consistent PTR, no blacklist hits, and a steady sending history. Shared IPs inherit the reputation of everyone on them.
Can I check a whole list at once?
This free tool checks one at a time. To verify a full list — email, phone and company together — upload a CSV to BounceBlock and preview your first 100 rows free.
Stop wasting hours on dead leads.
Upload your list and see how clean it really is — free, in under two minutes.
100 free creditsNo credit cardCancel anytime