AI SDR vs AI agents: what's the difference

"AI SDR" is the label on a lot of outbound software right now. The pitch is a sales development rep that never sleeps: give it a list of contacts, and it writes and sends the emails.

That covers one part of the job. A team of AI agents takes a different shape. Each agent owns one step of outbound, from finding the companies to booking the meeting, and the team runs on sending infrastructure and guardrails built for the volume. The difference decides how much of the work is still yours.

What is an AI SDR?

An AI SDR is software built to imitate one sales development representative (SDR). Most work the same way: you upload a list, connect a mailbox, and the bot writes an email for each person, sends it and follows up.

The writing is the headline feature. Everything before it, like who is on the list and what is known about them, and everything around it, like domains, mailboxes, warmup and limits, stays with you.

AI SDR vs AI agents, step by step

Outbound is six steps: find companies, find the people, research them, write, send and follow up, then handle replies and meetings. An AI SDR takes on two or three of them. A team of agents splits all six, one agent per step, each handing its output to the next. The post on what an agentic revenue platform is walks through each agent.

Why splitting the job matters

The list decides more than the writing. Example: Ostervane sells to logistics companies with 200–1,000 people, and a bought list of 1,000 contacts has 400 who fit. The other 600 emails go to people who will never buy, however good the copy. An agent that finds companies from your ideal customer profile fixes the input, not just the output.

Research is a job, not a merge field. A job title dropped into a template isn't research. An email that mentions Fennmarrow opened a second warehouse last month and is hiring three sales reps has a reason to be read. That takes reading the company and the person, for every person on the list.

Volume needs infrastructure. Example: 1,000 new people a month at 5 emails each is 5,000 emails, about 230 per working day. At 30–50 cold emails per mailbox per day, that's 5–8 warmed mailboxes on separate sending domains. A bot sending from one connected mailbox tops out near 50 a day, or burns the domain trying.

Control needs guardrails. Software that sends on its own needs hard limits: who never gets emailed, how soon anyone can be contacted again, how much each mailbox sends, and one way to stop everything at once. It also needs a choice of how much it decides, from approving every draft to running on Autopilot.

Questions to ask any AI SDR vendor

1. Where does the list come from? Do you bring it, or does it find companies from a description?
2. What does it research, and can you see it? Ask for the research behind a sample email.
3. Who sets up sending? Domains, mailboxes, DNS records and warmup, and how many emails each mailbox sends per day.
4. What keeps the wrong people out? Customers, open opportunities, partners, competitors, and anyone contacted last month.
5. How much does it decide? Can you approve drafts before they send, and set that per person?
6. What happens after a reply? Does the sequence stop, and who books the meeting?
7. How do you stop it? One switch, or a setting buried in every campaign?

If the answer to most of these is "you handle that", you're buying a writer with a send button, not a sales team.

How Leadgenerator.io splits the work

Leadgenerator.io is the Agentic Revenue Platform. Agents find companies that fit your description and can add new ones every day, find the right people and their email addresses, research each company and person, and write every first email and follow-up. They send in a sequence from warmed mailboxes, stop when someone replies, read the replies and book meetings.

Leadgenerator.io sets up new sending domains with 5 mailboxes each, created automatically when the domain verifies, and warmup keeps running in the background. Suppression lists, 60–90 day cooling periods, caps of 30–50 cold emails per mailbox per day and one switch that stops all outreach keep the agents inside your limits, and mode is set per person: Manual, Copilot or Autopilot.