This is a practical configuration walkthrough, not a review — see our full tool tier list and Instantly review if you're still deciding on a platform. This guide assumes Smartlead is the choice and walks through actually setting it up for agency use.
Unlimited sending accounts, a whitelabel workspace model priced per client rather than per platform-wide seat, and agency-specific features (sub-accounts, permissions, a master inbox) built into the core product rather than bolted on — see our white-label guide for the deeper mechanics of how this compares to alternatives.
Start with the agency's own master account on a Pro-tier or higher plan — this is what gives access to whitelabel workspace creation. Configure the agency's own branding at this level first (logo, custom domain for the client-facing dashboard) before creating any client sub-accounts, since this branding inherits down to every sub-account created afterward.
Each client gets their own workspace, priced as a per-workspace add-on on top of the master Pro plan. Inside each sub-account: connect that client's dedicated domains and mailboxes (never shared with another client — see our domains-per-client guide for the volume math), set up campaigns scoped to that client only, and assign team permissions so staff only see the client accounts they're actually working.
Configure warmup on every new mailbox before it touches a live campaign — a 4-week ramp is the standard baseline (see our warmup guide for the full schedule). Set warmup to run automatically on mailbox connection so this never depends on someone remembering to start it manually for a new client's infrastructure.
The master inbox consolidates replies across every connected mailbox and every client sub-account into a single unified view — this is the feature that actually makes managing 10+ client accounts workable instead of requiring separate inbox checks per client throughout the day. Set up reply categorization (positive, neutral, negative, out-of-office) so triage happens at a glance rather than reading every reply individually.
Smartlead's API exposes campaign-level metrics that can feed an external dashboard (Looker Studio is a common choice) rather than requiring a manual pull for every client's weekly report — see our client reporting guide for what that report should actually contain once it's automated. This is worth the initial setup time once client count makes manual reporting a real weekly time cost.
A Pro-tier plan or higher is generally the entry point for whitelabel workspace creation, with client sub-accounts then priced as a per-workspace add-on on top of that base plan.
It's safer to enable automatic warmup on mailbox connection rather than relying on someone remembering to start it manually for every new client's infrastructure — a 4-week ramp is the standard baseline before live sending.
It consolidates replies across every connected mailbox and every client sub-account into a single unified view, which is what makes managing 10+ client accounts workable without checking separate inboxes throughout the day.
Once client count makes manual weekly reporting a real time cost, yes — an API connection to a dashboard like Looker Studio removes the need to manually pull metrics for every client's report.
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Written by
Scott Holmes
AI systems consultant based in Barrie, Ontario. Founder of Pinnacle Tech Projects. Has configured Smartlead's agency infrastructure for multi-client cold email operations.
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