Frequently asked questions.

Whenever someone creates something new and exciting, there’s bound to be some curiosity! We asked our customers what some of their initial questions were to share with you.

Frequently asked questions.

Whenever someone creates something new and exciting, there’s bound to be some curiosity! We asked our customers what some of their initial questions were to share with you.

What is VTO?

View Time Optimization (VTO) by Verizon Media, as exclusively provided by Validity, delivers commercial mail to top inbox positions the moment mailbox users are active, driving more impressions, engagement, and revenue. Verizon Media mailboxes include Yahoo, AOL,,, among others, which comprise a meaningful portion of most email lists.

Verizon Media research showed marketing messages in the top inbox position had a 50% higher open rate than those in the third position and opens decreased dramatically in lower positions. This consumer inbox reality combined with a growing amount of commercial mail being sent creates congestion and competition for attention that is difficult to work around.

Supporting that claim, Validity customers have seen significant increases in open rates and click-through rates for campaigns that use VTO.

By combining VTO with Everest’s email reputation features, senders maximize their deliverability and the likelihood their mail passes global filters at Verizon Media, a requirement for an email to successfully receive VTO benefit.

Why do I have to use Everest to access VTO?

While VTO allows senders to deliver commercial mail to Verizon Media mailboxes in top inbox positions the moment a recipient is active in their mail app, VTO is a natural add-on for good senders who have a good reputation at mailboxes like Yahoo, AOL, and It’s a no-brainer, since your messages are already reaching the inbox. Now they’ll get to the top of the inbox.

The Everest platform will help you diagnose and repair sender reputation issues at all major mailbox providers, including Verizon Media. Combining Everest with VTO results in more mail delivered and more mail engaged.

Does VTO only work on specific mail clients/apps?

VTO works with any client the Verizon Media subscriber uses to access their inbox – whether on the web, through one of Verizon’s apps on iOS or Android, or through third-party apps like Apple Mail

Is VTO by Verizon Media a standalone product?

No. Senders wishing to access VTO must purchase an annual subscription of Everest. The VTO technology is fully integrated into the Everest platform, providing a one-stop shop to optimize your email program.

How is VTO different from Send Time Optimization (STO) at Verizon Media mailboxes?

STO is a “best guess” of when a user will be in their inbox based on previous engagement activity. VTO delivers mail to top inbox positions the moment users are active in their mail app, regardless of previous behavior.

VTO is a privacy-minded evolution of STO. Traditionally, with STO, senders have relied on customer engagement data to suggest a window of likely inbox activity. In contrast, VTO does not track past user behavior to determine when an inbox is likely to be active; it simply delivers an email right when Verizon Media subscribers check their inbox via a simple, automated queuing mechanism. Neither the timing of when the user checks their inbox, nor any personal data, is shared with the sender.

VTO is only available at Verizon Media mailboxes — Yahoo, AOL,,, and more — and is exclusively available as part of Everest from Validity.

How complicated is the process of implementing VTO into a campaign?

VTO works with any ESP and is easy to implement. You can send an email with VTO using nothing more than a sending domain and subject line. No coding to API, no ML/AI effort required. There are flexible implementation options available. Validity will help you identify the best method to implement (e.g., header tag, body tag, from address, subject line) depending on your ESP and their capabilities, as well as the complexity/sophistication of the campaign.

Which mailbox providers or email domains does VTO work on?

At this time, VTO technology works on Yahoo, AOL, and Netscape accounts.

Do I need to do anything custom or special to use VTO technology?

All you need to do is add a simple x-header to your campaigns so the VTO network can identify your email.

Does this just enable more spam?

No. By partnering with Validity and making this solely available within the Return Path platform, we make sure that spammers and bad-actors can’t abuse this technology.

How can I get VTO?

If you’re a Return Path customer already, contact your customer representative! If you are not yet part of the Return Path family, simply click the “Request Info” button at the top of this page to arrange a time to connect and discuss the benefits of Validiy’s entire suite of email marketing tools.

How is this different from Send Time Optimization (STO)?

While Send Time Optimization (STO) can address inefficient sending behaviors, competing models by various senders result in bulk deliveries to the same recipient at the same time, negating any of the benefits STO would ideally provide. By amplifying the “below the fold” problem, they further decrease the chance of opens and increase email fatigue.

How do I get VTO?

VTO is exclusively available as part of Everest, Validity’s industry-leading email deliverability solution. The combination of Everest and VTO is the gold standard for senders mailing to Verizon Media inboxes.

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