Smartlead vs Instantly vs Coldrig: how an assistant connects, and what each sells
Smartlead and Instantly are sending platforms with their own assistant connectors. Smartlead's license includes no mailboxes or domains; Instantly sells done-for-you Google accounts and domains on top of its plans. Coldrig is one price for the mailboxes, their domains, warmup and sending, with one hosted MCP server and 34 curated tools. This page lists what each vendor's own pages say, read on 2026-10-14, and makes no price ranking.
Does each one do the same job?
The job is mailboxes, domains, warmup and sending, run by an assistant with nothing done by hand.
| Smartlead | Instantly | Coldrig | |
|---|---|---|---|
| Mailboxes and domains | Not in the plans (they list 0 mailboxes). Bought separately through SmartSenders, from $13 a domain a year and $4.50 a mailbox a month for fresh Google or Outlook mailboxes. | Sold on top of the plans: done-for-you Google accounts at $5 a month each and domains at $15 a year. | Included in the price. Your assistant buys and sets them up. |
| Plans | Base $39, Pro $94, Unlimited Smart $174, Unlimited Prime $379 a month. | Growth $47 and Hypergrowth $97 a month. Growth shows replies as preview-only; replying inside its inbox is listed on Hypergrowth. | $49 a month for 3 mailboxes, $59 for 5, $84 for 10, $134 for 20, $334 for 60. |
| Assistant connector | A hosted MCP server that works only over SSE. The setup is a settings-file entry with your API key in the address, and Node.js must be installed. | A hosted MCP server. Paste a link that holds your API key (or send it as a header). Its help article says 31 tools across 5 categories, and its developer docs say every API action is exposed, including placing done-for-you account orders. | One hosted MCP server, 34 curated tools, plus a REST API and a CLI. Connect with your API key, or sign in and press Allow in an app that supports OAuth, such as ChatGPT's custom connector. |
| Reported tool count | Not stated in its help article. | 31 (help article); every API action per its developer docs | 34, one hosted first-party MCP server |
A larger tool count may reflect broader capability, finer control, or simply a more granular object model. Count alone does not decide fit. See the scoped comparison of Coldrig's 34 intent-level tools with larger vendor surfaces, including where the larger surface is the better choice.
What is each one best for?
- Smartlead fits teams that already source mailboxes elsewhere or through SmartSenders, and want a large sending suite with a client-workspace model for agencies.
- Instantly fits teams that want a sending platform that can also order done-for-you accounts and domains through its API, and are happy to pay for the plan and the accounts separately.
- Coldrig fits teams that want their assistant to run the whole job, mailboxes through sending, with a single API key and a single price.
For a side-by-side monthly cost at 3, 5, 10, 20 and 60 mailboxes, see the comparison page. For Smartlead on its own, see Coldrig vs Smartlead.
Related
- Coldrig compared: real monthly cost at 3 to 60 mailboxes.
- 34 intent-level tools vs larger vendor MCP surfaces — lifecycle coverage and control tradeoffs.
- Coldrig vs Salesforge / Forge Stack.
- Do you need a separate infrastructure provider and sending platform?
- How to run cold email with your AI coding agent.
Sources and verification
- Smartlead: pricing and MCP server help article (read 2026-10-14)
- Instantly: pricing, MCP help article, MCP tools and done-for-you order endpoint (read 2026-10-14)
- Coldrig pricing