DNS Lookup

Perform a DNS lookup against multiple widely used nameservers around the world.


Select record type:
Enter a domain:


"250ok has built a best-of-breed platform that addresses the concerns of today's data-driven marketers."


Len Shneyder
VP of Industry Relations at SendGrid

Hey Sender! See how 250ok can help you monitor DNS issues.



More Free Tools

Blacklist Checker

Instantly check an IP or domain against major email blacklists including Spamhaus, SURBL, SORBS, and more.


Use Blacklist Checker


CIDR to IP Range

Enter a CIDR notation to instantly convert it to an IP range.


Use CIDR to IP Range

SPF Analyzer

SPF is a method to prevent email sender address forgery. Enter your domain to analyze its SPF record.


Use SPF Analyzer


IP Range to CIDR

Enter a IP range to instantly convert it to a CIDR notation.


Use IP Range to CIDR

DMARC Wizard

Enter your domain to analyze your DMARC record or create a DMARC policy for your domain.


Use DMARC Wizard


DNS Lookup

Perform a DNS lookup against multiple widely used nameservers around the world.


Use DNS Lookup

Resources for #SeriousSenders


Retailers, failure isn’t an option: Clarify your email strategy with a free webinar on July 19.

Email deliverability is tied directly to retail businesses’ financial success. If people don’t see your emails, they can’t click your emails, and thus, cannot purchase things from you. Bad news. When you consider you likely require log-in to complete a purchase, if they don’t get that password reset or any other critical UX components (think […]

Navigate through the email jungle with the 250ok Deliverability Guide.

We get it. We’re email deliverability nerds, but you (likely) aren’t. If you are, that’s awesome and we should be pals. But if you’re not, that’s okay, we’re still here to support you in all your email efforts. How? By giving you the map you need to be confident you’re sending your marketing and transactional […]

Introducing 250ok Prospect: World-class customer vetting and sales prospecting.

We’re back at it! Today we’re excited to unveil the latest addition to the 250ok suite: 250ok Prospect. Since some of the 250ok team worked at email service providers (e.g., ExactTarget/Salesforce, Marketo, Adobe, Oracle, SparkPost, SendGrid), we know one of the most significant challenges they face is gaining insight into customers that have not yet […]




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