Inside one of Canonbury Group’s inboxes, a manager named Daniel tags @Anton in a comment thread about outstanding invoices. He asks for a change to how invoice due dates are calculated for clients on 30-day payment terms. “On it,” Anton replies. A few minutes later: done. The invoicing logic is updated in the codebase, the change is tested, and the summary is posted back into the thread, right under the email it relates to.

Anton isn’t an employee. He’s an AI agent Canonbury built themselves, and he works where the team works: in the comment threads of their email.

Canonbury is a UK holding company that buys smaller private businesses and operates them well, a model far more common in the US than at home. Co-founder Alex Collins and his business partner Dan started in 2019 and have acquired 14 companies since, consolidating them into four active businesses spanning property inspections, field services, and other operations that run on consistent client relationships and a constant flow of email. About 100 people work across the group today, with roughly 42 of them spending their day in Missive, the team email app where the whole portfolio’s communication now lives, across 40 connected accounts.

None of this was the plan when they bought their first business. Back then, the plan was just to escape Outlook.

Seven logins, zero visibility: Outlook after the acquisition

Every company Canonbury acquired was running on Outlook, and for the original staff it worked. The problem was the management layer that came with the acquisition itself. Alex and Dan needed visibility across multiple businesses at once: to see what was coming in, assign it, escalate it, and know whether it had ever been handled. Outlook has no mechanism for any of that. Emails got forwarded once, then again, then a third time, and eventually landed somewhere with no indication of whether the original request had been resolved or had simply disappeared.

The login problem compounded things. One acquired company had seven separate inboxes. That’s seven Outlook accounts, seven individual logins, with operations staff signing into each one and trying to monitor all of them in parallel. There was no shared queue, no way to see who had what, and no way to coordinate without picking up the phone.

Outlook’s archive window made it worse. On high-volume service inboxes, the archive went back roughly two to three months before messages were simply gone. For a holding company trying to maintain continuity across businesses, the tool wasn’t just limiting. It was actively hiding what was happening across the portfolio. Remember that archive problem; it comes back later in this story.

Three guys in Quebec answering every ticket

Early in the acquisition run, Alex went looking for something that could sit on top of email and provide the management layer Outlook was missing. Two names came up: Front and Missive. He tried both.

Front looked like the safer choice. But the support comparison wasn’t close. Philippe, Rafael, and Etienne, Missive’s co-founders, were personally responding to tickets. Alex had come across Philippe through the IndieHackers community. “Front’s the established one, it’s significantly more expensive, but the support isn’t anywhere close to as responsive as Missive’s.”

From the second acquisition onward, Missive was non-negotiable for every new business. Staff typically start off skeptical, and Alex and Dan gave the same speech every time: it’s going to feel strange, you’re going to hate it, and in three months you’ll say you can’t imagine going back to Outlook. Alex estimates they’ve had that conversation 30+ times now.

“There’s a very high hit rate,” he says, “of people being like, oh my God, we’d be lost without Missive.”

Canonbury has each of their businesses as separate teams within one organization in Missive, managing all 40 accounts across the portfolio in one place, including SMS via Twilio. Cross-business collaboration became possible: a person in one business could be pulled into a thread involving another, billing simplified, and the entire group finally had one place to work from.

The killer feature: comment threads and the end of “has someone seen this?”

The original draw was what shared inboxes could do that Outlook couldn’t: assign conversations, close them out, and give everyone visibility into who had what. But the feature that changed how the team actually worked was one Alex hadn’t been shopping for. “The comment threads were the killer feature,” he says. “Because it means you stop all the forwarding. Has someone seen this? Has someone seen that? All of that goes away.”

The internal discussion stayed attached to the email itself, visible to everyone on the conversation, with nothing fragmenting across a chain of forwards. Alex now says that even with one business, one team, and one inbox, they’d still use Missive, primarily for that in-thread collaboration.

The onboarding sticking point was consistent: staff coming off Outlook needed time to build a new mental model around archive, close, and watch. Alex and Dan developed a short explanation they give every new team member. Archive means “I’m done with this, but it still exists.” Close means “this is finished for everyone.” Watch means “keep me notified even if nobody tags me directly.” Once it clicked, adoption held. People who had been dragged off Outlook stopped wanting to go back.

Anton: the AI agent who answers in the thread

Which brings the story back to Anton, named after a character from Silicon Valley, and not something Canonbury had planned when they first adopted Missive.

The mechanics are simple. When someone needs something, they tag @Anton in a comment the same way they would tag a teammate. The mention fires a webhook to Canonbury’s server, where Anton does his work, then replies back into the thread through the Missive API. No separate panel, no extra window, no MCP. Just webhooks, the API, and the comment thread everyone is already in.

The design was deliberate. Alex and Dan built Anton before Missive shipped its own AI assistant, and Alex still prefers the in-thread approach to any separate AI window. Unlike most AI email tools that require pasting context somewhere else, Anton arrives already knowing what the conversation is about. “The best part about all of this is that the agent has the context of the email or the chat conversation,” Alex says. “That’s the most powerful part.” Nobody has to summarize the situation or copy in the thread.

And that Outlook archive problem from the early days? Canonbury solved it themselves: they rebuilt the portfolio’s full email history, terabytes going back years, in a Supabase/Postgres database, and gave Anton access. When an email is lost to Outlook’s archive window, someone tags Anton and he goes and finds it. From there, his reach kept growing: ERP systems, their CRM in Airtable, financial records in Xero, Aircall call transcripts, and the codebase itself. A salesperson tags Anton to create a new client record. A manager asks him to update an invoicing rule; Anton raises a pull request. Alex runs a leaderboard across the organization celebrating the most creative Anton use cases, drawing entries from staff in different businesses who know each other only through Missive.

From “you have to use Missive” to “you want to use Missive”

For the first few years, Alex and Dan were the forcing function. Use Missive. It’s non-negotiable. Here’s why. The resistance was real, with every acquisition. Eventually it gave way, staff came around, and the management layer Outlook could never support was working.

Then Anton changed the adoption dynamic altogether. Teams that might have pushed back on migrating off Outlook have a different reason to care now. Missive is where Anton works. Anton is what they need. The argument Alex used to have to make now makes itself.

“Before, it would be: if you don’t use Missive, you’re in trouble. Now it’s: you have to use Missive because otherwise you can’t use Anton. And once you start using the agent you will not want to go back!”