Overview
GTMx is an outbound agency founded by Joshua Solomon that runs cold email campaigns for B2B clients. One of those clients was a fintech company, and GTMx had already done the hard part: the team had found message-market fit and knew exactly which offer was driving positive replies.
Then the campaigns stopped landing. Almost overnight, deliverability collapsed and reply rates fell below 0.5%. GTMx had a winning offer that wasn’t reaching the inbox, and the client relationship was at risk.
The challenge
GTMx wasn’t cutting corners. The team was already following the standard playbook: rotating domains and inboxes, keeping copy short and sending without links. None of it moved the needle.
The client sold into professional services and finance firms, and buyers like that sit behind strict email security. Their mail runs through enterprise gateways like Barracuda on top of Microsoft and Google, and GTMx’s emails were missing the inbox at all three. Switching infrastructure providers didn’t fix it either.
The problem wasn’t the message or the list. It was the reputation of the domains the emails came from: new domains that inbox providers had no reason to trust yet.
For an agency, that’s the worst kind of problem. The client sees the reply rate, not the root cause, and a campaign that stops producing replies is a campaign that gets cancelled.
The solution
Mission Inbox started with a simple question: which email would you trust more, one from a domain registered two weeks ago or one from a domain registered ten years ago? The client already owned the answer. Its primary domain had years of history and a strong reputation, exactly the kind of sender strict filters are built to let through.
How it worked:
- Audit the domain first. Mission Inbox reviewed the reputation of the client’s primary domain and used that data to decide how many subdomains it could safely support. No guesswork.
- Build on trust that already exists. Mission Inbox set up subdomains under the client’s primary domain, so every one of them carried the trust of a domain with real history behind it.
- Dedicated SMTP inboxes on every subdomain. Sending volume was spread across the subdomains in line with what the audit showed the domain could carry.
- Nothing else had to change. GTMx kept its campaigns, its offer and its workflow. Only the infrastructure underneath changed.
- Hands-on onboarding. The Mission Inbox team handled setup end to end, so the client’s campaigns were back in market fast.
“When Tony asked me which email I’d trust more, one from a domain registered two weeks ago or one from a domain registered ten years ago, it immediately clicked for me.” Joshua Solomon, Founder, GTMx
The results
Deliverability recovered almost immediately, and the setup has stayed healthy since. What changed:
- Reply rates back above 5%, up from under 0.5%, on the same offer and the same campaigns.
- More leads than before the drop. Lead volume didn’t just come back, it passed where it had been.
- 2,000 to 4,000 emails a day across the subdomains, still sending months later with no burned domains, no constant rebuying and no rewarming.
- The client stayed. Instead of losing the account, GTMx went on to serve the fintech client for many more months.
Customer quote
“Our campaigns went back to reply rates above 5%, and lead volume didn’t just return, it exceeded where we’d been before. That turnaround let us keep serving the client for many more months.” Joshua Solomon, Founder, GTMx
Secondary quote
“The onboarding and setup from the Mission Inbox team was outstanding from start to finish.” Joshua Solomon, Founder, GTMx
The takeaway
When reply rates drop, people usually blame the copy, the list or the offer. GTMx had all three right. The real problem was trust.
The fastest route back to the inbox is often a domain the business already owns: Mission Inbox audits it, sizes how many subdomains it can carry, and builds dedicated inboxes on them.
“If you’re working with a client whose primary domain has a strong reputation, Mission Inbox is well worth a try.” Joshua Solomon, Founder, GTMx
No aged domain of your own? Lease one inside Mission Inbox. Same setup that worked for GTMx: 1 aged domain, 25 subdomains, 3 mailboxes each, 75 mailboxes, 2,250 emails/day.
FAQ
Why did reply rates fall below 0.5% if the offer was working?
The message and the list weren’t the problem. The emails came from new domains that inbox providers had no reason to trust yet, and the client’s buyers sat behind Barracuda on top of Microsoft and Google.
Didn’t domain rotation, short copy and no links help?
No. GTMx was already doing all three. Switching infrastructure providers didn’t fix it either.
What did Mission Inbox actually change?
It audited the client’s primary domain, set up subdomains under it, and put dedicated SMTP inboxes on every subdomain. Volume was spread in line with what the audit showed the domain could carry.
Did GTMx have to change its campaigns?
No. GTMx kept its campaigns, its offer and its workflow. Only the infrastructure underneath changed.
How much volume does the setup send?
2,000 to 4,000 emails a day across the subdomains, still sending months later.
What if I don’t have an aged domain?
Lease one inside Mission Inbox. The GTMx-style setup is 1 aged domain, 25 subdomains, 3 mailboxes each: 75 mailboxes and 2,250 emails/day.
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