How Unit21 scaled enterprise outbound without risking its primary domain

Overview

Unit21 helps banks, neobanks, fintechs and payments companies detect fraud and money laundering. Its go-to-market team needed to scale outbound into enterprise accounts, but the existing setup created a serious domain reputation risk.

Before Mission Inbox, outbound emails were being sent from individual rep inboxes on Unit21’s primary domain, unit21.ai. That meant cold-send activity was tied to the same domain the company relied on for customer and investor communication.

For a company selling fraud and compliance software, that risk was not acceptable. Unit21 needed dedicated infrastructure that could support outbound growth without exposing the domain the business runs on.

The challenge

Unit21’s team wanted to scale enterprise outbound, but every send was running through its primary domain. Volume was capped at roughly 100 emails per inbox per day, and every cold email added risk to the same domain reputation used for important business communication.

The existing shared-IP setup was also not well matched to the inboxes Unit21 was trying to reach. Their target buyers included banks and fintechs using filters such as Microsoft, Proofpoint and Mimecast. Reverse-DNS mismatches were also hurting placement.

The internal bar was high too. Unit21’s security team needed confidence that any outbound setup could scale safely, avoid exposing the root domain, and pass a full vendor security review before being used in production.

The solution

Mission Inbox rebuilt Unit21’s outbound sending operation on dedicated, isolated infrastructure.

Cold outbound moved onto subdomains under unit21.co, running on Mission Inbox dedicated IPs. This kept cold-send activity separated from unit21.ai, so the primary domain stayed protected from outbound reputation risk.

Mission Inbox also helped partition reputation by purpose. A dedicated marketing subdomain was used to keep high-volume sends separate from sales outreach, while unit21.io was warmed in parallel and held as a backup domain.

The team did not need to change its workflow. Sending continued through Mission Inbox’s API, so Unit21 could keep its existing tools and processes while moving delivery onto infrastructure it could control.

Mission Inbox also handled deliverability work, including SPF and DMARC alignment, domain whitelisting for reply routing, and MI Shield filtering to catch problem emails before they could damage reputation.

The results

With Mission Inbox in place, Unit21 opened an enterprise outbound channel it had not been able to scale safely before.

The team could reach senior decision-makers at target accounts without sending cold email from the primary domain. Outbound now scales across Unit21’s NeoBank and Payments segments without touching unit21.ai.

Mission Inbox also reduced pressure on the rep team. Instead of squeezing volume through a small number of personal inboxes, Unit21 could send through dedicated infrastructure built for the use case.

When a deliverability issue was flagged, Mission Inbox diagnosed and resolved it the same day, confirming delivery with zero bounces. Most importantly, the primary domain stayed protected throughout.

Customer quote

“Mission Inbox opened up a channel we hadn't really had before. It takes a lot of pressure off our reps and lets us do more than we could on our own.” Nicholas Bennett, GTM Engineer, Unit21

Secondary quote

“Tony's our guy for anything infrastructure or deliverability related.” Jonathan Duan, Head of Business Development, Unit21

The takeaway

For companies selling into regulated or enterprise buyers, outbound infrastructure cannot be treated casually. If cold email runs through the same domain used for customer, investor and internal communication, the risk is too high.

Unit21 used Mission Inbox to separate cold outbound from its primary domain, scale enterprise outreach on dedicated infrastructure, and keep control over the email reputation its business depends on.