Gmail Promotions Tab: Annotations Preview

Email annotations bring your promotions to life with images, deals, expiration dates and more.

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.


Use DNS Lookup

Resources for #SeriousSenders


Email on Tap Episode Eight, with Angela Vega, Senior Marketing Manager, Vrbo

We’re back with another entry in our Email on Tap video series! Anthony Chiulli, 250ok’s director of product marketing, sat down with Angela Vega, senior marketing manager at vacation rental company Vrbo (formerly known as HomeAway) at the Email Evolution Conference in Savannah, Georgia. They chat a bit about Vrbo’s approach to email marketing, including […]

250ok Announces Lead Sponsorship of Juncos Racing Team for Indy 500

250ok Announces Lead Sponsorship of Juncos Racing Team for Indy 500 Local Indianapolis SaaS company to sponsor Juncos Racing and driver Kyle Kaiser Indianapolis – May 22, 2019 – 250ok, an Indianapolis-based email intelligence platform, today announces its lead sponsorship of the Juncos Racing team for the 2019 Indianapolis 500. 250ok’s chief executive officer Greg […]

Analytics meets Design: Preview weighting!

As promised, we’re taking a magnifying glass to 250ok Design’s newest features. We’ll start with something encapsulating the biggest differentiator of our email previewing and testing tool: device-rendering weighting! Now, your device and email client renderings will be presented to you in order of most importance. When we originally created 250ok Design, we were adamant […]




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