---
title: 'What Is a Sales Development Representative and What Do They Do?'
description: >-
  A sales development representative (SDR) is a rep who books qualified meetings through cold outreach. Learn what SDRs do, their metrics, and how the role works.
date: '2026-08-12'
lastUpdated: '2026-08-12'
author: Arthur Grishkevich
category: Sales Development
keywords:
  - what is a sales development representative and what do they do
  - sdr role
  - sales development representative job
  - sdr vs bdr
  - sdr metrics
---
# What Is a Sales Development Representative and What Do They Do?

A sales development representative (SDR) is a sales rep who generates and qualifies new pipeline through outbound outreach, mainly cold email, cold calls, and LinkedIn. SDRs do not close deals. Their job is to identify target accounts, contact prospects, handle early objections, and book qualified meetings that account executives turn into revenue.

## Key Takeaways

- An SDR is a top-of-funnel rep whose core output is qualified meetings booked, not closed deals or signed contracts.
- SDRs typically own one channel mix: cold email, cold calling, and LinkedIn outreach, layered with research and CRM hygiene.
- A single warmed mailbox tops out at roughly 30 to 50 sends per day at steady state, which caps how much cold email one SDR can run per inbox.
- Reply rate is the clearest test of deliverability for SDR email: any reply, even "not interested," proves the message reached a human inbox.
- Alchemail's outbound engine booked 927 meetings and generated over $55M in client pipeline in 2025 using 200+ sending accounts across 100+ domains.
- Deliverability and infrastructure come before copy and personalization, because the best message cannot rescue email that lands in spam.

## What does a sales development representative do day to day?

An SDR spends the day building lead lists, sending cold emails, making cold calls, and running LinkedIn outreach to book qualified meetings for account executives. A typical day mixes prospect research, personalized outreach at volume, follow-up sequencing, objection handling on replies, and updating the CRM. The end product is a calendar of meetings with buyers who fit the ideal customer profile.

The concrete tasks break down roughly like this:

| Activity | Purpose | Typical time share |
|---|---|---|
| Prospecting and list building | Find accounts and contacts that match the ICP | 20-25% |
| Cold email and sequencing | Reach prospects at scale and follow up | 25-30% |
| Cold calling | Live conversations to book meetings faster | 15-25% |
| LinkedIn outreach | Warm touchpoints and social selling | 10-15% |
| CRM updates and reporting | Track status, log activity, keep data clean | 10-15% |

The channel mix varies by company. Some SDR teams are call-heavy, others email-heavy. For teams that lean on email, infrastructure decisions determine whether that effort ever reaches an inbox. See our guide on [cold email deliverability fundamentals] for how sending setup shapes results.

## What is the difference between an SDR and a BDR?

An SDR (sales development representative) usually handles inbound and marketing-sourced leads, while a BDR (business development representative) usually handles outbound cold outreach to net-new accounts. In practice the titles overlap and many companies use them interchangeably. Both roles share the same goal: qualify prospects and book meetings for account executives who own the closing conversation.

The cleanest way to read the distinction:

| Dimension | SDR (common definition) | BDR (common definition) |
|---|---|---|
| Lead source | Inbound, demo requests, content leads | Outbound, cold, net-new accounts |
| Primary channel | Email and phone follow-up | Cold email, cold calling, LinkedIn |
| Starting temperature | Warmer, shown some intent | Cold, no prior relationship |
| Core metric | Qualified meetings booked | Qualified meetings booked |

Do not over-index on the labels. What matters is which motion you are running. If your growth depends on reaching people who have never heard of you, read [how to build a cold outbound motion] before hiring for either title.

## What metrics measure SDR performance?

The primary SDR metric is qualified meetings booked, because that is the pipeline the closing team actually works. Supporting metrics for email-led SDRs include total reply rate, positive reply rate, and meetings-to-pipeline conversion. Activity counts like emails sent and calls dialed matter as leading indicators, but they are inputs, not outcomes. Judge SDRs on booked meetings and the pipeline those meetings produce.

For SDR teams running cold email, reply rate is the clearest test of a domain's deliverability. Reply rate is the share of contacted prospects who respond at all. If people reply, even to say "not interested," the email reached the inbox and a human read it. Positive reply rate then forecasts pipeline. Both matter for different reasons.

Open rate is the unreliable metric here. Open rate is the share of recipients who supposedly viewed an email, measured by a tracking pixel. Those pixels are blocked or pre-fetched by mail providers, so the number is noise. If any SDR email metric deserves the "vanity" label, it is open rate, not reply rate. For that reason we run outbound with open tracking off. More detail lives in [why open rate is the wrong metric].

| Metric | What it measures | How to read it |
|---|---|---|
| Meetings booked | Qualified calls on the calendar | Primary outcome metric |
| Positive reply rate | Interested replies / contacted | Forecasts pipeline |
| Total reply rate | Any reply / contacted | Deliverability signal |
| Pipeline generated | Dollar value of sourced opportunities | Business result |
| Emails sent / calls made | Raw activity | Leading input only |

## How many prospects can one SDR realistically reach by email?

One SDR is capped less by effort and more by mailbox infrastructure. A single warmed mailbox tops out at roughly 30 to 50 sends per day at steady state. Sending past that ceiling burns reputation and pushes email into spam. To reach thousands of prospects per week without wrecking deliverability, you distribute volume across many accounts and domains instead of overloading one inbox.

This is why volume math for SDR email is an infrastructure question first. At 40 sends per day per mailbox, reaching 4,000 prospects a week requires many mailboxes working in parallel. Alchemail runs 200+ sending accounts across 100+ domains for exactly this reason: to spread volume within the per-mailbox ceiling rather than push high volume through a small number of inboxes.

Deliverability and infrastructure come before copy. The best-written cold email cannot rescue a message that lands in spam. Personalization only pays off once deliverability, targeting, and offer are already right. If you are scaling SDR email output, start with [how to scale sending domains safely] rather than rewriting subject lines.

## Should you hire an SDR or outsource the function?

Hire an in-house SDR when you have a defined ICP, a tested offer, and a manager who can coach the role, and outsource when you need pipeline faster than you can build sending infrastructure and hire. In-house gives you control and product depth. Outsourcing gives you existing deliverability infrastructure, warmed domains, and a team that has already solved inbox placement at scale.

The trade-off usually comes down to time and infrastructure. Building your own outbound engine means acquiring domains, warming mailboxes over weeks, and learning deliverability the hard way. A managed outbound partner brings that stack ready. In 2025, Alchemail's outbound engine booked 927 meetings and generated over $55M in client pipeline using its own multi-domain infrastructure. For a framework on this decision, see [in-house vs outsourced SDR].

## FAQ

### What does SDR stand for in sales?

SDR stands for sales development representative. An SDR is a sales rep who sits at the top of the funnel and focuses on generating and qualifying new pipeline through outbound outreach. They do not close deals. Their output is qualified meetings booked for account executives, who then run the sales process through to a closed contract.

### Is an SDR an entry-level job?

Yes, the SDR role is usually an entry-level sales position and a common on-ramp into a sales career. Reps typically start as SDRs to learn prospecting, cold outreach, objection handling, and CRM discipline, then move into account executive or closing roles. Because it is skills-focused rather than seniority-focused, strong SDRs can advance within one to two years at many companies.

### Do SDRs make cold calls or send cold emails?

SDRs typically do both, plus LinkedIn outreach. The channel mix depends on the company and the buyer. Call-heavy teams prioritize live conversations; email-led teams prioritize scaled sequences. For email-led SDR work, remember that a warmed mailbox caps at about 30 to 50 sends per day, so reaching thousands of prospects requires many accounts and domains, not one overloaded inbox.

### What is a good reply rate for SDR cold email?

There is no universal number because reply rate depends on list quality, offer, and deliverability, but total reply rate is the clearest test of whether your email is reaching inboxes at all. Any reply, including "not interested," confirms the message landed and a human read it. Track total reply rate as a deliverability signal and positive reply rate as your pipeline forecast.

### How many meetings should an SDR book per month?

Meeting quotas vary widely by market, deal size, and channel, so a fixed number is misleading. Judge SDRs on qualified meetings booked and the pipeline those meetings produce, not on activity counts. For context on what a well-run outbound engine can produce, Alchemail booked 927 meetings across clients in 2025, generating over $55M in pipeline through 200+ accounts and 100+ domains.

### What tools does an SDR need?

An SDR needs a CRM, a data or list-building source, an email sequencing tool, and sending infrastructure with warmed mailboxes and multiple domains. Phone dialers and LinkedIn tools round out the stack for those channels. The most overlooked piece is deliverability infrastructure, because copy and personalization only pay off after the email actually reaches the inbox.

### What is the difference between an SDR and an account executive?

An SDR generates and qualifies pipeline; an account executive (AE) closes it. The SDR books qualified meetings through outbound outreach and then hands the prospect to the AE, who runs discovery, demos, negotiation, and the closing conversation. Splitting the roles lets SDRs specialize in high-volume prospecting while AEs focus on managing and closing active deals.