Instantly is one of the most widely used sequencers in cold email, and for good reason. Their AI Copilot can write copy, generate sequences, and spin up campaigns end-to-end. Their Lead Finder gives you access to 450M+ B2B contacts inside the same platform. And they've kept the UX genuinely approachable for teams that don't want to stitch together five tools.
When you pair Instantly with ScaledMail's managed infrastructure, you get a clean two-layer stack: Instantly running the AI sequencer and lead data, ScaledMail running the inboxes underneath. Here's why that pairing works so well for teams running serious volume, and exactly how to set it up.
Who Instantly Is For
Instantly is built for teams that want an all-in-one AI outbound workspace: sequencer, warmup, lead data, and reply automation in one tool. The features that make it a strong sequencer partner:
- AI Copilot and AI agents: Create Sales Agents, Reply Agents, and an AI Email Writer that drafts sequences from a prompt. For lean teams, this is a real time saver.
- Lead Finder (450M+ contacts): Waterfall work email enrichment with multiple providers built in. You can source leads and launch campaigns without leaving the platform.
- Unlimited email accounts and unlimited warmup on every paid tier. You only pay for sending volume, not per-inbox.
- Clear volume tiers: $47/mo for 5K emails/month, $97/mo for 100K emails/month, $358/mo for 500K+ emails with Private Deliverability Network. Annual billing comes with a 20% discount.
- SISR (Server and IP Sharding and Rotation): Instantly's higher tiers include dedicated/private server and IP blocks with automatic flagged-IP swapping, which is valuable for teams running serious volume.
- Workflow automation: Automatic routing when leads visit your site, reply, or book a meeting. Saves manual campaign triage.
- Approachable UX: Instantly is consistently praised for being easy to set up and use, which matters when you're onboarding team members who aren't cold email specialists.
Why the ScaledMail + Instantly Pairing Works
Instantly is an excellent sequencer. ScaledMail is a dedicated infrastructure provider. The cleanest cold email stacks separate those two jobs, and when you do, both sides get better at what they do.
Division of Labor
Instantly runs the AI workflows, sequences, reply handling, and lead data. ScaledMail provisions your sending inboxes, configures SPF/DKIM/DMARC, keeps warmup aligned, and monitors mailbox health day-to-day. Two layers, zero overlap.
Isolated Mailbox Infrastructure
ScaledMail provisions Google Workspace and Microsoft 365 accounts on isolated tenants. Your ESP reputation is entirely your own, not shared with other customers. That isolation matters because sender reputation within an ESP is what drives placement over the long term. Instantly's sending layer connects to isolated inboxes via OAuth and sends through reputation you control.
Aligned Philosophy on Deliverability
Instantly's Private Deliverability Network and SISR system show they take deliverability seriously at the sending layer. ScaledMail operates the same way at the mailbox layer. You get deliverability attention from both sides of the stack, which matters when something drifts and you need to diagnose fast.
ESP Diversification at the Inbox Layer
Instantly is the sequencer. ScaledMail controls the ESP mix. We provision Google Workspace and Microsoft 365 across isolated tenants. When Google tightens filters in a given quarter, your Microsoft inboxes keep delivering. When Microsoft rolls out new filtering, Google picks up the slack. Instantly connects to both via OAuth. You assign inboxes to campaigns and the sequencer handles scheduling across your pool.
How the Stack Works Together
Clean division of responsibility:
- ScaledMail: Domain acquisition, DNS authentication (SPF, DKIM, DMARC), mailbox provisioning on Google Workspace and Microsoft 365, compatibility with 2:1 warmup ratio maintained permanently via your warmup tool, deliverability monitoring, blacklist remediation, domain rotation, pre-aged domain inventory.
- Instantly: Campaign sequences, AI Copilot, Lead Finder and waterfall enrichment, reply detection, unified inbox, workflow automation, analytics, AI agents, built-in warmup for your connected inboxes.
Instantly connects to your ScaledMail inboxes via OAuth. It sends through those inboxes. ScaledMail keeps them healthy, warmed, and properly authenticated. You run campaigns in Instantly. We manage the infrastructure underneath.
Setup Process
Step 1: Spec Your Infrastructure
Book a call or use the infrastructure calculator. We need:
- Target daily cold email volume across all clients and campaigns
- Number of active Instantly workspaces (one per client or one per internal campaign line)
- ESP preference (we recommend mixing Google Workspace and Microsoft 365)
- Launch timeline (pre-aged domains available for same-week launch)
Volume planning: 15-25 cold emails per inbox per day on Google Workspace, 5-10 per day on Microsoft 365. Every inbox maintains a 2:1 warmup ratio permanently. For every 1 cold email sent, 2 warmup emails run through your warmup tool. That ratio runs continuously, more than during initial warmup.
To send 1,000 cold emails per day: roughly 50-65 Google inboxes across 25-33 domains, plus a 20-30% rotation buffer. We'll give you exact numbers based on your targeting geography and volume pattern.
Step 2: We Build the Infrastructure
Our team handles the full build:
- Domain selection: .com preferred. No hyphens, no numbers, no spam trigger words. Every domain forwards to your main business website.
- DNS configuration: SPF, DKIM, and DMARC records configured and verified on every domain. DKIM propagation can take up to 48 hours. We monitor until it resolves correctly.
- Mailbox provisioning: Google Workspace and Microsoft 365 accounts provisioned on isolated tenant infrastructure.
- Warmup activation: ScaledMail is compatible with Instantly's built-in warmup and with external warmup tools. Fresh domains run a 14-day warmup period. Pre-aged domains (30, 90, or 180 days old) are campaign-ready faster.
Standard 40-inbox build: 24-48 hours. You don't touch DNS. You don't log into GoDaddy or Namecheap. We deliver ready-to-use credentials.
Step 3: Connect to Instantly
Once inboxes are warmed and deliverability is verified, connect them to Instantly via OAuth:
- Navigate to Email Accounts → Add New Account
- Select Google or Microsoft as the connection type
- Authorize via OAuth. One-click for Google Workspace and Microsoft 365
- Set the daily sending limit to the number we specify for that inbox
- Assign inboxes to the appropriate workspace or campaign rotation
For agencies connecting 30+ inboxes, we export a structured CSV with all credentials. Instantly supports bulk inbox import for large setups.
Step 4: Campaign Configuration in Instantly
With ScaledMail inboxes connected:
- Daily limits: Match what ScaledMail specified per inbox. These numbers are calibrated to the 2:1 warmup ratio and ESP-specific safe zones.
- Sending window: 8am-6pm recipient timezone for B2B. Instantly handles timezone detection, configure it correctly and let it work.
- Open tracking: Turn it off. Apple Privacy preloads content, making open data meaningless. Tracking pixels also trip spam filters. Track replies instead.
- Sequence length: 1-2 email touches, then 90 days dark. Most positive responses come from email #1. Longer sequences spike complaint rates.
- AI Copilot: Use it for personalization snippets and first-draft sequences. Then edit for voice and specificity. AI is a starting point, not a finished output.
- Workflow automations: Instantly's site-visit and reply routing is genuinely useful. Set these up early so you're not manually triaging positives.
Step 5: Bounce Rate Management
Target bounce rate under 1.5%. Instantly's Lead Finder includes waterfall email verification, which handles most of this automatically. If you're uploading leads from external sources, run them through LeadMagic plus BounceBan before upload. If bounce rate climbs above 1.5% in Instantly's analytics, pause that campaign and re-verify the list before resuming.
Domain Rotation with Instantly
We manage domain rotation on the infrastructure side using a 2-batch system:
- Batch A sends actively for 3 weeks
- Batch B rests (minimum 1 send per day to maintain warmup engagement)
- After 3 weeks, batches swap
In Instantly, this means we periodically update which inboxes are in your active rotation. We handle the scheduling and notify you in Slack when batches swap. Your active inbox pool stays fresh without you managing it manually.
Domain longevity: high-engagement campaigns keep domains 12-18 months. Lower-engagement campaigns, we plan for replacement every 5 months. Isolated infrastructure removes one variable from that equation.
Where Instantly + ScaledMail Fits Best
This stack works especially well for:
- Teams that love Instantly's AI Copilot and Lead Finder but want the deliverability layer handled by specialists
- Agencies running multiple client campaigns where per-client inbox isolation matters
- Operations scaling past 50+ inboxes where DIY infrastructure management becomes a full-time job
- Teams that want to pair Instantly's Private Deliverability Network with isolated mailbox tenants for defense in depth
- Anyone who wants Instantly's UX and workflow automations without running DNS and domain operations themselves
If you're evaluating other sequencers alongside Instantly, Smartlead + ScaledMail works equally well and EmailBison + ScaledMail is the premium option for high-volume agencies needing single-tenant sequencer isolation.
What Customers Running This Stack Tell Us
"Been with ScaledMail since March 2025, have placed multiple orders and have been happy with the service. They give you a dedicated slack channel and are very responsive on any questions I have. I've used both Google and Microsoft inboxes with them, all have worked well for me."
. Dustin
"ScaledMail has saved us a ton of time buying domains and setting up inboxes, which we used to do manually in-house. Their team are very supportive, and the response time is perfect. Bonus points for end-to-end delivery with sequencer setup."
. Growth Labz
"I audibly said 'wow' within 24 hours of using ScaledMail. I was blown away by the speed of their execution and the thoroughness of their processes. Every detail is accounted for, and I've never had a more hands-off experience."
. Aaron Gusinov, CEO, LeadForce Solutions
Frequently Asked Questions
Does ScaledMail work with Instantly's built-in warmup?
Yes. Instantly includes unlimited warmup on every tier, and ScaledMail inboxes work with it directly. Maintain the 2:1 warmup-to-cold ratio continuously, more than during the initial 14-day period.
How do I structure inbox-to-workspace assignment in Instantly?
Clean separation per client or campaign type. Assign a dedicated inbox pool to each Instantly workspace. ScaledMail can provision isolated batches per client so that one client's sending behavior doesn't affect another's inbox reputation. For agencies, this is the right architecture.
Can I keep my existing Instantly campaigns and just swap in ScaledMail inboxes?
Yes. Your sequences, lead lists, and analytics stay in Instantly. We provision new inboxes, configure DNS, and deliver credentials. You connect them in Instantly's Email Accounts panel and assign them to existing or new campaigns.
Should I still use Instantly's Lead Finder if I have ScaledMail inboxes?
Yes. Lead Finder is a sourcing and enrichment tool. That is separate from the sending infrastructure. Use whichever lead source fits your targeting. Instantly's 450M+ database is a strong starting point.
How fast can I get ScaledMail inboxes live in Instantly?
With pre-aged domains: 24-48 hours from order to campaigns running. With fresh domains: 14-day warmup period, then live. Most agencies keep a standing inventory of pre-aged inboxes for rapid client onboarding.
Do I need to disable Instantly's open tracking?
Yes. Apple Mail Privacy Protection preloads email content, which means open rate data is fabricated. Every Apple Mail user shows as "opened" regardless of whether they opened the email. Tracking pixels also trip spam filters. Track replies only.
Do Instantly's SISR/Private Deliverability Network features conflict with ScaledMail inboxes?
No. SISR operates at Instantly's sending infrastructure layer. ScaledMail operates at the mailbox layer. They're complementary. SISR handles server/IP rotation on Instantly's side, ScaledMail handles ESP-level mailbox isolation on yours.
Get Started
Running Instantly or evaluating it for your stack? Book a call to spec your infrastructure, or build your custom package now.
Month-to-month. No annual lock-in. Pre-aged domains available for same-week launch.