# Best Cold Email Software for a Lead Generation Agency With Many Clients (2026)

URL: https://warmerly.com/blog/best-cold-email-software-for-lead-generation-agencies
Published: 2026-10-14
Reading time: 7 minutes
Tags: Comparison, Cold email, Agencies, Tools

> How Smartlead, Instantly, Woodpecker, Saleshandy, lemlist and Warmerly handle many client accounts, client access, white label and billing for agencies.

For a lead generation agency, the tools that describe client structure most fully are Smartlead (client accounts with white label as a paid add-on), Woodpecker (an Agency Panel priced per active client) and Saleshandy (unlimited clients, with white label under Enterprise). Instantly keeps each client in a separate workspace, but every workspace needs its own subscription. Warmerly's Agency plan gives you unlimited client workspaces on one bill and one shared pool of mailboxes, but it has no white label and no client-only login. Which is right depends on whether clients log in, whether they should see your brand, and how you want extra clients to be billed.

> **How this was checked**: Every vendor detail below was read on the vendor's own pricing or help pages on October 14, 2026. Where a page was unclear or contradicted itself, we left the figure out or say so. Prices change, and several pages show more than one price, so confirm before you buy. Warmerly's details come from our own code and internal docs. We make Warmerly, which is on this list, so weigh that when you read the verdicts.

## Cold email software for agencies with many clients, compared

**How cold email tools handle many clients, checked October 2026 on each vendor's own pages**
| Tool | How clients are kept apart | Client login or view | White label | What more clients add to the bill |
| --- | --- | --- | --- | --- |
| Smartlead | Client accounts with their own permissions and credit allowances | Yes, clients get a login; reply-only access is described | Yes, as an add-on at $29 a month per client workspace | Clients start on Pro ($94 a month); Prime ($379) includes 3 clients; add-on price per extra client not shown on the page |
| Instantly | Separate workspaces, each with its own campaigns, contacts and analytics | Team roles including View / VA Access; client portal not described | Not mentioned on its pricing or workspace pages | Each workspace requires its own subscription |
| Woodpecker | Agency Panel add-on with a separate prospects database per client | Client view-only access; clients connect their own mailboxes without sharing passwords | Listed at $5 a month per active client; what it covers is not described on the pricing page | $27 a month per active client for the Agency Panel |
| Saleshandy | Separate teams or workspaces, unlimited clients from one account | Not described | Listed under Enterprise | Not clear which plans include unlimited clients |
| lemlist | Not described for agencies | Teammate invites and shared campaigns | Not mentioned | Priced by the number of users |
| Warmerly | Unlimited client workspaces on the Agency plan, each with its own mailboxes, campaigns, leads and inbox | No client-only login; people you invite join as owner, admin or member | No | Nothing per client. All clients share the Agency plan's allowances; $179 a month |

## What a lead generation agency should check

- Separation. Each client's mailboxes, leads and replies should sit apart, so one client's problem never touches another's and you can close a client cleanly. Instantly's help page notes an email account can connect to only one workspace at a time.
- Client access. Some agencies send clients a login, some send a report, some give clients nothing. Decide which you do before comparing tools, because it rules several out.
- White label. If you resell the software or want clients to see your brand and domain, only some tools offer it, usually as an add-on or a higher plan.
- What an extra client costs. Per-workspace subscriptions, per-client add-ons and one shared pool all behave very differently at 5 clients and at 25.
- Where the capacity limit is. Mailboxes, emails a month, contacts and leads per campaign are capped differently by each tool. Add up all your clients, not one.
- The inbox. When you answer replies for 20 clients, check whether the inbox shows all of them together or one client at a time. See our guide to unified inboxes for cold email replies.

## How each tool handles many clients

### Smartlead: the most complete client and white label setup we found

Smartlead's help center describes a Client Access Dashboard. You add a client with a name, company and email, choose their permissions and Master Inbox categories, and allocate email and lead credits. Its white label article says clients can use the app under your branding and domain name with your logo, and mentions a restricted, reply-only access option, for example showing a client only Interested replies. Its pricing page says the option to add clients starts on the Pro plan ($94 a month), Prime ($379 a month) includes 3 clients, and white labeling is an add-on at $29 a month per client workspace. The pricing page shows client limits as icons rather than numbers, so ask Smartlead how many clients your plan holds before you commit. If you want to resell the tool under your own brand, this is the closest fit of the six.

### Instantly: a workspace per client, a subscription per workspace

Instantly's help center says workspaces are completely separate spaces, mainly meant for agencies that used to keep a login per client. Each has its own campaigns, contacts and analytics, you use one login and switch from the logo, and team roles include Admin, Editor and View / VA Access. The cost point is stated plainly: "Each workspace requires its own subscription." Three clients means three subscriptions, each of which can be on a different plan. That is clean separation and simple per-client costing, and it is a good fit if you want to pass each client's tool cost straight on. It is a poor fit if you want one shared pool. We did not find a client portal or white label on Instantly's pricing or workspace pages. Its pricing page also shows conflicting price sets, so we quote no Instantly price here.

### Woodpecker: an Agency Panel priced per active client

Woodpecker sells an Agency Panel add-on at $27 a month per active client. Its pricing page lists a separate prospects database, all client stats in one panel, client view-only access, clients connecting their own mailboxes without sharing passwords, automated audits of client domains and centralized billing. White label is listed separately at $5 a month per active client, but the pricing page does not say what it covers; its agency page mentions a client reporting app on your domain with your branding. As arithmetic only: 10 active clients is $270 a month for the panel, on top of the base plan. Every plan has unlimited team members and email accounts, per its pricing page. That per-client model is easy to resell, and it costs more as the number of active clients grows.

### Saleshandy: unlimited clients, white label on Enterprise

Saleshandy's pricing page says you can "Run outreach for unlimited clients from one account" and create as many separate teams or workspaces as you need, each with its own members and settings. It lists white label, running the platform under your own brand and domain, under Enterprise. The page does not make clear which plans include unlimited clients, so confirm that with Saleshandy. We found no further agency detail on a second Saleshandy page.

### lemlist: strong for teams, silent on agencies

lemlist's pricing page says pricing is based on the number of users and lists teammate invites and shared campaigns. It does not mention agencies, client workspaces or white label. That does not mean lemlist cannot be used for client work, only that we could not verify a client structure, so ask before you plan around it. If your agency sells multichannel outreach with LinkedIn steps and personalised images, lemlist may still suit you better than a tool built around mailbox volume.

## Warmerly's Agency plan

On the Agency plan ($179 a month) you can create as many client workspaces as you need. Each has its own mailboxes, campaigns, leads and inbox, and none carries its own subscription: they draw on the Agency plan's allowances as one pool, and everything is billed to the Agency workspace. The pool is 100 mailboxes in total across all clients, 250,000 active prospects, and 100,000 leads in a single campaign, with no cap on active campaigns and no cap on emails sent (each mailbox keeps its own safe daily limit). Warmup runs on every connected mailbox, and API access and webhook alerts are included on Agency. A new client workspace skips the setup wizard and starts with your sender details already filled in. Email, LinkedIn and WhatsApp campaigns run from the same account; LinkedIn accounts are billed separately.

> **Where Warmerly is the weaker pick**: There is no white label: anyone you invite sees Warmerly, not your brand. There is no client-only login or client view: people join a workspace as owner, admin or member, so giving a client access means giving them a full member seat. The 100 mailboxes are a total for all clients, there is no published plan above that, and hosted OneMail mailboxes are ordered on the Agency workspace, not inside a client workspace. The inbox shows one workspace at a time, and we found no combined view across clients. If you resell the software under your brand or give clients a restricted login, Smartlead or Woodpecker is the better pick. If each client must carry its own invoice, Instantly's one subscription per workspace is the simpler model.

## Which one should you pick?

- You resell the tool under your own brand and domain: Smartlead (add-on per client workspace), or Woodpecker's white label. Check exactly what each white label covers first.
- Clients log in to see replies or reports: Smartlead's client access, or Woodpecker's view-only access.
- Each client should have its own subscription and invoice: Instantly.
- You want a cost that does not rise with each client, and you manage the accounts yourself: Warmerly Agency, up to 100 mailboxes in total.
- You run a small team and mostly one brand, not a client roster: lemlist, or a smaller plan elsewhere.

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Source: https://warmerly.com/blog/best-cold-email-software-for-lead-generation-agencies
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