Fintech Outbound, Run as an Experiment
Most growth-stage fintech companies don't actually know who their outbound buyer is yet. Is it the controller drowning in reconciliation? The CFO who owns the budget? The founder who feels the pain personally? And which message moves them — cost savings, compliance coverage, or speed to close the books? Before you hire SDRs, you need data, and Instantly is built for exactly this kind of parallel testing: a simple campaign builder, A/Z variant testing, and campaign analytics that tell you which combination of persona and pitch is actually converting.
What Instantly doesn't provide is the sending infrastructure underneath those experiments. Running five parallel campaigns means real sending volume across many mailboxes, and every test is worthless if the emails never reach an inbox. That's ColdRelay's job — the secondary domains, mailboxes, and dedicated IPs that Instantly sends from. This guide covers how fintech teams wire the two together and run a clean experimentation program that finds the repeatable motion.
Why Run Instantly on ColdRelay Infrastructure
Instantly's pitch to experimenters is generous: paid plans support unlimited email accounts, so you can connect as many sending mailboxes as your tests require. But Instantly connects mailboxes — it doesn't provision them. The domains, DNS records, IP reputation, and tenant isolation behind those accounts are the infrastructure layer's problem, and in an experimentation program that problem compounds: a deliverability wobble in one mailbox pool silently skews the results of whichever campaign it's attached to, and you end up killing a value prop that actually worked.
ColdRelay solves the infrastructure half. You order dedicated mailboxes on isolated Azure tenants with dedicated IPs, fully DNS-configured (SPF, DKIM, DMARC) and ready in about an hour. There's no warmup waiting period before your first experiment either — warmup runs continuously as part of each mailbox's 4 sends/day budget (2 outbound + 2 warmup), so a new test cell can launch the same day you think of it.
The pairing is additive, not competitive: ColdRelay is the infrastructure, Instantly is the sending and sequencing layer on top. You keep Instantly's campaign builder, A/Z testing, Unibox, and analytics — you just run them on mailboxes consistent enough that your experiment data means something.
Visit Instantly →Connecting ColdRelay Mailboxes to Instantly
Provision a test-sized mailbox pool on ColdRelay
Pick secondary domains adjacent to but separate from your primary fintech domain. ColdRelay supports 100-150 mailboxes per domain, so a single domain comfortably carries an entire experimentation program — most teams start with 30-90 mailboxes sized to the number of test cells they plan to run. Everything provisions on isolated Azure tenants with dedicated IPs in about an hour, with SPF, DKIM, and DMARC already configured.
Bulk-import the mailboxes via CSV
Export your mailbox list with SMTP/IMAP credentials from the ColdRelay dashboard, then use Instantly's bulk SMTP/IMAP import to connect the whole pool in one upload. With unlimited email accounts on Instantly's paid plans, there's no per-account ceiling forcing you to ration test cells.
Set sending limits and assign mailboxes per campaign
Set each account's daily sending limit in Instantly to 2 outbound emails per day, matching ColdRelay's per-mailbox budget — 4 sends/day total per mailbox, split 2 outbound + 2 warmup. Then assign a dedicated slice of mailboxes to each test campaign (say, 10 mailboxes per cell) so deliverability is held constant across experiments and your variable is the message, not the sender.
Build one campaign per test cell in the campaign builder
Create a separate Instantly campaign for each persona-vertical combination you're testing — controllers at lending startups, CFOs at payments companies, founders at seed-stage fintechs. Inside each campaign, use Instantly's A/Z variant testing to rotate value props: one variant leads with cost, one with compliance, one with speed. Personas live at the campaign level, value props at the variant level — that's what keeps the readout clean.
Launch, then read campaign analytics weekly
Let every cell run for at least two weeks before judging it. Instantly's campaign analytics break out opens, replies, and positive replies per campaign and per variant — review them on a fixed weekly cadence, kill the losers, and shift their ColdRelay mailboxes to the winners. Scaling a winning cell is an infrastructure order, not a rebuild: add mailboxes on ColdRelay and import them into the winning campaign.
The Fintech Instantly Playbook
Test one variable per layer
The fastest way to ruin an outbound experiment is changing two things at once. Hold persona constant within a campaign, vary the value prop across A/Z variants, and keep the mailbox slice fixed for the duration of the test. If the controller campaign with the cost-savings variant wins, you know exactly why — and exactly what to scale.
Score positive replies, not opens
Fintech buyers open everything and commit to nothing — open rates will mislead you. Tag replies in Unibox as positive, neutral, or negative, and rank test cells by positive-reply rate per 100 sends. A campaign at 1.5% positive replies beats one at 4% raw replies full of unsubscribes, and it's the number an SDR team can actually be hired against.
Set kill criteria before you launch
Decide in advance what ends a test: for example, under 0.5% positive replies after 300 sends kills the cell, over 2% graduates it to scale. Pre-committed thresholds stop you from nursing a CFO campaign for months on hope — and because ColdRelay provisions new mailboxes in about an hour, the cost of killing a cell and standing up a new hypothesis is nearly zero.
Graduate the winner into a documented motion
The output of this whole program isn't pipeline — it's a spec. When one persona-prop-vertical combination consistently clears your threshold, write down the list definition, the winning copy, the sequence timing, and the observed conversion math. That document is what you hand your first SDR, and the difference between hiring into a proven motion and hiring into a guess is usually two quarters of burn.
Typical Fintech Outbound Benchmarks (Instantly + ColdRelay)
| Metric | Benchmark | Notes |
|---|---|---|
| Inbox placement rate | 95%+ | Dedicated IPs and pre-configured SPF/DKIM/DMARC keep deliverability constant, so differences between test cells reflect the message |
| Positive reply rate, winning cell | 1.5-3% | The best persona-prop combination after 2-3 test rounds; losing cells often sit under 0.5% |
| Outbound capacity per mailbox | 2/day | 4 sends/day total per mailbox — 2 outbound + 2 warmup |
| Sends needed to judge a test cell | 300-500 | Roughly 2-3 weeks with 10 mailboxes per cell at 2 outbound sends/day each |
| Time from hypothesis to live test | Same day | ~60 minutes to provision on ColdRelay, plus CSV import and campaign setup in Instantly |
What It Costs: Instantly + ColdRelay
You pay per mailbox per month for the infrastructure, with volume tiers that drop as you scale (see the table below). DNS, dedicated IPs, and isolated Azure tenants are included — and since one domain carries 100-150 mailboxes, a full experimentation program rarely needs more than one or two domains.
Instantly is billed separately on its own subscription for the campaign builder, A/Z testing, Unibox, and analytics — and because paid plans include unlimited email accounts, connecting more ColdRelay mailboxes doesn't raise your Instantly bill.
Infrastructure cost scales with mailbox count; Instantly's cost is essentially flat as you add accounts. That makes the marginal cost of one more test cell almost entirely a ColdRelay line item — cheap enough to test aggressively before committing SDR salaries to a motion.
| Mailboxes | ColdRelay price / mailbox / month |
|---|---|
| 1–199 | $1.00 |
| 200–999 | $0.85 |
| 1,000–4,999 | $0.70 |
| 5,000+ | $0.55 |
Each mailbox sends 4 emails per day — 2 outbound to prospects + 2 warmup. ColdRelay provisions mailboxes on isolated Azure tenants with dedicated IPs; Instantly handles the sending, sequencing, and inbox rotation on top.
Frequently Asked Questions
Does ColdRelay replace Instantly?
No — they're complementary layers. Instantly handles the campaign builder, A/Z variant testing, Unibox, and campaign analytics; ColdRelay provides the domains, mailboxes, and dedicated IPs that Instantly sends from. Fintech teams use both together: Instantly runs and measures the experiments, ColdRelay makes sure every cell actually reaches an inbox.
How many mailboxes do I need to run persona and value-prop tests in parallel?
Budget roughly 10 mailboxes per test cell. At 2 outbound sends/day per mailbox (4/day total including 2 warmup sends), that's 20 sends/day per cell — enough to hit a 300-500 send readout in two to three weeks. Three personas tested in parallel means about 30 mailboxes; one ColdRelay domain carries 100-150, so even an ambitious test matrix fits on a single domain.
Won't deliverability differences between mailboxes contaminate my test results?
That's exactly the risk ColdRelay's setup is designed to remove. Every mailbox runs on isolated Azure tenants with dedicated IPs, identical pre-configured SPF/DKIM/DMARC, and the same steady 4 sends/day budget (2 outbound + 2 warmup) — so placement stays uniform at 95%+ across your pool. When the sending layer is held constant, a difference between campaigns is a difference in message, which is the whole point of the experiment.
Do I have to wait through a warmup period before launching my first test?
No. ColdRelay mailboxes don't have a separate warmup phase — warmup runs continuously as 2 of each mailbox's 4 daily sends, alongside your 2 outbound sends. Provisioning takes about an hour, so a hypothesis you form in the morning can be a live Instantly campaign the same day.