Cold email infrastructure for teams that want to send, not to configure MX records.

Business-to-business outreach is a long-established channel and remains widely used by sales and BD teams across every major economy. Most jurisdictions distinguish clearly between B2B prospecting (where the contact is relevant to the recipient's professional role) and consumer marketing (where stricter consent rules apply). We provide infrastructure for the former. The legal posture in your audience's jurisdiction is your responsibility — we provide the deliverability and the engineering, you provide the campaign and the targeting decisions.

Rule of thumb based on operating actual client programmes: to send 10,000 well-paced cold emails per month without burning any single mailbox, you want 10 to 20 mailboxes in a rotating pool spread across 3-5 sending domains. To scale to 50,000 per month, 30 to 50 mailboxes across 15-20 domains. Above 100,000 you need a properly engineered pool with domain rotation, IP diversity and continuous monitoring. The chart on this page shows the curve. The wrong answer is "send everything from one mailbox to look like a real person" — Gmail and Microsoft both detect that pattern within weeks.

A fresh mailbox on a brand new domain has zero sending reputation. Hit it with 50 cold emails on day one and Gmail will file them in spam or drop them altogether — you can verify this yourself with a test campaign and Postmaster Tools 48 hours later. Our pre-warmed mailboxes have 2 to 4 weeks of synthetic engagement and real-traffic warmup under their belt before you start sending — which means your outreach starts from a healthy baseline instead of a buried grave. The cost of skipping warmup is not a percentage hit on placement; it is the entire campaign landing in spam for a month while you try to figure out why.

Yes. We deliver mailboxes with OAuth tokens ready to drop into your platform of choice. Instantly, Smartlead, Lemlist, Apollo, Reply.io, Woodpecker, Lemwarm, Outreach.io — they all speak the same language for OAuth and we have tested every current major platform. We deliver a CSV with mailbox addresses, OAuth tokens, recommended daily sending limits, and the sending domain map. You import; you start sending.

The honest 2026 answer is 15 to 30 cold emails per day per mailbox to a fresh recipient list. Smartlead and Instantly will technically let you send 50-100; the platforms are not the throttle, the inbox provider is. Gmail and Microsoft both detect sustained sending above ~30 cold/day from a non-established address as bulk-pattern behavior. We recommend starting at 15/day for the first 4-6 weeks of a new mailbox in your pool and ramping to 25-30/day once placement signals are stable. Above 30/day per mailbox you are accelerating reputation decay; below 10/day you are wasting infrastructure capacity.

We monitor inbox placement daily across a private seed-list test set covering Gmail, Outlook, Yahoo and iCloud. When a mailbox's placement drops below 70% on Gmail or Outlook for two consecutive days, the system pauses new sending from that mailbox, runs a recovery warm-up routine, and — if recovery fails after 7 days — replaces it with a fresh pre-warmed mailbox from the pool. Your platform sees a mailbox swap notification; your campaigns continue uninterrupted; you do not lose campaign state. This is the operational difference between us and a DIY setup.

Three differences. First, infrastructure: we operate at scale and can spread risk across many domains and IPs in ways a single team cannot easily replicate. Second, monitoring: we run continuous seed-list testing per ISP per mailbox; you cannot get that visibility from inside any single sending tool. Third, replacement: when a mailbox burns, we swap in a pre-warmed replacement within hours, not days. The DIY path works for low volumes (under 5,000 cold emails per month) and for teams with one engineer dedicated to it. Above that, the math favours managed infrastructure — and the math has tightened in 2026 because Google Workspace per-seat pricing increased while flat-rate competitors emerged.

Every mailbox we ship is configured to comply with the bulk sender requirements that came into force in February 2024 and tightened through May 2025: SPF passing alignment, DKIM 2048-bit rotating, DMARC at policy p=quarantine or p=reject, one-click unsubscribe in headers (RFC 8058), complaint rate below 0.1% maintained through engagement-core warmup. Microsoft's parallel May 2025 rules are also covered. We update configurations when ISPs change requirements; that is part of the service.

Yes — Agency plan is built for this exact case. Custom sending domains under your brand convention, isolated workspaces per client (so one client's reputation cannot affect another), white-label monitoring dashboards, branded reporting if you want to share placement metrics with end clients. Pricing is volume-based; the more clients you onboard, the better the per-mailbox economics. We have agencies running 80-200 mailboxes for their book of business through our Agency plan.

We can. The pattern is recognizable: you ran a campaign whose volume or content tripped one of the platform's automated reputation systems, and you got a suspension or shadow-ban notice without recourse. The fix is rarely about begging support; it is about new mailbox infrastructure on fresh domains. We provision the new pool, you migrate sequences, the old pool is decommissioned. Recovery to full sending takes 3-4 weeks because the new pool needs its own warmup period — anyone promising faster is selling you a recipe for re-suspension. Same protocol applies if you got banned from Google Workspace itself.

Honest answer: when your monthly cold volume is under 5,000 emails and you have technical resources internally. At that scale, buying 5 Google Workspace seats yourself, configuring DNS once, and using Lemwarm or Smartlead's built-in warmup will be cheaper than our Starter plan. Also wrong fit: when your "cold email" is actually consumer marketing dressed up as B2B (sending to personal Gmail addresses with no business context), or when your offer requires sending the same recipient 7+ touches in 30 days. Those programmes will burn any infrastructure, ours included; the issue is the campaign, not the rails.

No. We work with clients running outbound to lists built from Apollo, ZoomInfo, LinkedIn Sales Navigator, RB2B, Clay, or comparable B2B prospecting tools where contacts are professional roles relevant to your offer. We do not work with clients spamming purchased consumer lists, scraped Facebook/Instagram followers, or anything where the recipient has no plausible professional reason to receive your message. The reputation damage from that kind of programme is unrecoverable, and our other clients suffer from contagion. We turn down 1 in 3 prospective clients on this question alone.