30% More Sends, 50% Less Admin: How ActiScale Automated Its Mailbox Stack on InboxKit

On paper, mailbox pricing looked the same across providers. In practice, none of them gave ActiScale a reliable end-to-end process, so the team hired VAs just to manually connect mailboxes back and forth to their sending tools.

Our setup was the following: we used different providers, we tried Icemail and others, but nobody could actually give us a reliable process end to end. The cost of infrastructure was pretty much the same everywhere, but only on paper, because you pay per mailbox the same, but what we had to do was get VAs connecting these mailboxes back and forth, because we could not take our own time and do it manually.

— Thomas Tzouridis, CEO of ActiScale

What stood out most was InboxKit's built-in sequencer connection. Instead of manually shuttling mailboxes into a sending tool, ActiScale could connect the API once and let new mailboxes route themselves.

The greatest thing about InboxKit is they have a sequencer. No matter what you're using, whether it's Instantly, Smartlead, or Warmy for warmup, you can just connect the API to the sequencer, select the mailboxes, and they get transferred automatically. This was a huge advantage for us.

— Thomas Tzouridis, CEO of ActiScale

Over time, ActiScale found Microsoft mailboxes outperformed Google mailboxes on InboxKit, at the same per-mailbox price. That gave the team a choice: send more without paying more, or run the same volume on fewer mailboxes.

What we saw over time is that Microsoft mailboxes perform better than Google mailboxes. We can send more emails at the same health rate. You have two choices: either increase your volume and pay the same for the mailboxes, which is better for your outreach, or drop your cost because you don't need that many mailboxes.

— Thomas Tzouridis, CEO of ActiScale

ActiScale also avoided the SMTP route some competing providers pushed them toward.

Icemail was way harder, the processes weren't automated, so you ended up doing most of it manually or needed employees doing it. Another provider, MailDozo, wanted us to use SMTPs to get good pricing on Google and Microsoft mailboxes, but what we've seen across our customers is that normal Google or Microsoft mailboxes perform way better than SMTPs. In InboxKit, you don't need to use any SMTP, you get Google or Microsoft mailboxes directly.

— Thomas Tzouridis, CEO of ActiScale

Setup speed matched the rest of the pitch. Domains bought directly through InboxKit were ready in about 10 minutes; domains connected from elsewhere propagated within 30 minutes. Full mailbox setup, including uncommon domain types, ran about an hour.

We were directly live in InboxKit, it was easy to set up. If you buy domains directly in InboxKit, you have them within maybe 10 minutes. If you connect your own domains, they're fully propagated and usable within a maximum of 30 minutes. You can use any domain provider you want, even for a special domain like a .ch we needed for one client. The mailboxes were fully set up within one hour. There was no learning curve, it's very simple, and it just works.

— Thomas Tzouridis, CEO of ActiScale

At the time of this interview, ActiScale was running roughly 1,600 mailboxes across its full client base on InboxKit. The person managing that infrastructure barely has to log in.

Right now we're using 1,600 mailboxes in total for all of our customers, all hosted in InboxKit. My employee who handles this barely even uses InboxKit, because everything just runs end to end as expected. The only time he uses it is when we onboard a new customer and need new mailboxes, or when we're changing mailboxes for a customer targeting a new market.

— Thomas Tzouridis, CEO of ActiScale

Two numbers changed for ActiScale after the switch: what they paid for mailboxes, and how much staff time the infrastructure required.

There are two big things that changed in our numbers. First, the cost for mailboxes, because with InboxKit you get Microsoft mailboxes at the same price as Google mailboxes, and Microsoft mailboxes have better health, so we send 30% more emails per mailbox than with Google mailboxes at the same health rate, which dropped our cost immensely. Second, the time: the employee dedicated to mailboxes had his time spent on them go down by more than 50%. He could handle more work, and that extra time went into better campaign tracking and better accounts overall.

— Thomas Tzouridis, CEO of ActiScale

• Mailbox admin stops needing a VA. The sequencer integration replaced manual mailbox-to-sequencer handoffs, cutting the time ActiScale's team spent on infrastructure by more than half.
• Microsoft pricing parity changes the math. Better-performing Microsoft mailboxes at Google prices meant 30% more send volume per mailbox at the same health rate, without paying more.
• No SMTP tradeoff. Where another provider pushed ActiScale toward SMTP sending to get good pricing, InboxKit gave them real Google and Microsoft mailboxes directly, which they'd found performed better across client split tests.
• Support doesn't stop on weekends. Issues got fixed within 15 to 30 minutes over Slack, weekends included, at no extra cost.

It's a clear 10. I wouldn't know anything they could do better. They're responsive within a minute, not just on weekdays but also on weekends, and they resolve issues within about 30 minutes, at no additional cost. If you're on the fence, there's almost no risk, register an account and try it with 10 mailboxes. If I'm wrong, you lose almost nothing. If I'm right, it's a huge advantage for your agency.

— Thomas Tzouridis, CEO of ActiScale, rating InboxKit 10/10

ActiScale is a cold email agency that builds done-for-you outbound departments for high-ticket B2B service providers, handling infrastructure and campaigns end to end so clients book qualified sales calls. The agency is led by CEO Thomas Tzouridis and runs roughly 1,600 mailboxes across its client base on InboxKit.

For the operational side of running this across many clients at once, our agency workflows guide covers how agencies structure multi-client infrastructure day to day.

Running outbound for clients?

InboxKit provides the mailboxes, domains, automated DNS, warmup, and sequencer integrations that let agencies cut mailbox admin time and scale sending without adding headcount. See plans and pricing or explore our agency email solution.