The 250ok Advantage

From stronger coverage to a best-practice approach to seed testing, you gain an advantage when using 250ok Inbox.

Optimized Seed Testing

Seedlist Optimizer (patent pending) enables you to weigh your results based on the composition of your email lists. Stop testing providers you don't mail to.

Learn more about Seedlist Optimizer

Automated Monitoring & Alerts

Live outside the app with custom email, SMS, Slack, HipChat, PagerDuty, and webhook alerts. Set it and forget it. Focus on what matters to you, free of pointless notifications.

Learn more about 250ok Alerts



Comprehensive Coverage

Enjoy 250ok's unparalleled coverage of B2B and B2C mailbox providers around the globe. Track your inbox placement and deliverability in real time to pinpoint and resolve issues.



Expert Services & Support

You won't find any junior-level script readers here. Ask for examples of deliverability issues 250ok diagnosed, triaged, and quickly resolved after other competitors failed.

Learn more about 250ok Experts

Why use seedlist testing?

Seedlist testing reveals if your mail is passing global filters at Gmail, Microsoft, Yahoo/AOL, and all other providers.

When sending commercial email, it's important to understand what's likely to happen the next time you send to a recipient at a particular mailbox provider. Are your messages hitting SPAM at Yahoo! or going missing at Comcast? Are you sacrificing ROI because you lack the proper visibility into performance? Seedlist-based inbox monitoring is a key data point in solving this issue.

READ BLOG

Do you need email certification and panel data?

Old-school solutions to modern challenges are not a recipe for success. That's why we love debunking sender mythology — so you don't get burned.


Myth #1: Everyone Needs Email Panel Data!

No, everyone sending commercial email today already owns the most relevant panel in the world: the people they're sending mail to. With currently available panel offerings there is no statistical significance for most senders and the data is often misleading and hazardous given its severe biases.

Myth #2: Email Certification is a Smart Investment!

For most senders – not all – the juice is no longer worth the squeeze. Cert won't help you at Gmail, the largest mailbox provider in the world. Based on changes in the modern email landscape, 250ok customers combine best practices with expert services to achieve world-class performance.

Myth #3: Seedlist-based Inbox Testing is Dead!

While some vendors downplay the value of seedlist testing, do so at your own peril. Seeds are like spam traps: by the time the red flag goes up, there's already a problem. They are a critical component in testing perimeter defenses like blacklists, global spam filters, and reputation in general.

Resources for #SeriousSenders


We can’t wait to explore Savannah haunts during the Email Experience Conference.

We are a proud supporter of the Email Experience Council (eec), and this year, we’ll be a sponsor of their Email Evolution Conference (presented with the ANA) in Savannah, Georgia on April 24-26. We’ll be at Booth #22, so you won’t have to get crafty for a 250ok sighting. In fact, we’re scheduling meetings in […]

We’ll fit in perfectly in the City of Angels next month.

Take flight with us as we travel to another Digital Summit, this time in Los Angeles. We’ll be in the City of Angels for two days, from April 10-11, to listen to incredible speakers, network with like-minded professionals, and hopefully meet you fine folk! We’ve also got our Director of Marketing Sam Douglass III presenting […]

Are you overseeding when testing your deployments?

Recently at 250ok we’ve had a few conversations with new clients and partners about some of the seeding advice they received from other deliverability solution providers monitoring inbox placement rates (IPR) for their brands. When we talk about seeding, we’re talking about a variety of possibilities; brands sending multiple versions of their newsletters, utilizing a […]




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