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CrewAI Multi-Agent SystemsRole Delegation & Human Review

Equip CrewAI agent teams with safe email capabilities with human-in-the-loop review

Let autonomous agent crews draft, verify, and dispatch transactional emails without risk. Built-in human approval mode holds high-stakes emails in your operator queue for inspection before delivery.

3,000 emails/month freeZero credit card requiredSub-20ms edge latency
202 Accepted
Dispatch Speed
Queued durably before any provider call
Human-in-Loop
Safety Mode
Dashboard approval hold
6,000/mo
Free Tier
Custom domain DKIM
Developer Ergonomics

Drop into your application in under 60 seconds

Native typed interfaces with zero unnecessary dependencies. Built for standard fetch and modern edge runtimes.

$pip install sadasend crewai
crewai_email_tool.py
python
PYTHON
import os
from crewai.tools import tool
from sadasend import SadaSend

client = SadaSend(api_key=os.environ["SADASEND_API_KEY"])

@tool("Send Customer Update Email")
def send_customer_update(recipient: str, subject: str, content: str) -> str:
    """Dispatches a transactional customer update email via SadaSend.
    Held in human approval queue if approval_required is enabled on the key.
    """
    res = client.emails.send(
        from_email="updates@yourdomain.com",
        to=recipient,
        subject=subject,
        html=f"<div style='font-family: sans-serif;'>{content}</div>",
        tags=["crewai-task"]
    )
    return f"Email submitted. Dispatch ID: {res.id}"

Custom CrewAI tool decorated with @tool for multi-agent delegation across Researcher, Writer, and Dispatcher roles.

Core Infrastructure

Engineered for high deliverability and zero incident risk

Every layer from edge connection pooling to per-key rate limits is designed to keep critical transactional dispatches fast, reliable, and contained.

Multi-Agent Delegation Architecture

Separate responsibilities cleanly: let research agents draft email copy while dedicated communication agents execute dispatches.

Human-in-the-Loop Review Mode

Hold agent-composed emails in your SadaSend dashboard queue for review before actual delivery to real customer inboxes.

Domain & Recipient Sandboxes

Restrict test crew runs to company email domains to guarantee developmental agent mistakes never impact real clients.

Velocity Protection Circuit Breakers

Prevent rogue agent loops across multiple crew iterations from burning sending quotas or triggering spam filters.

Full Audit Trail for SOC 2

Track which agent executed each dispatch, the prompt parameters used, and synchronous delivery confirmation IDs.

6,000 Free Monthly Sends

Deploy your CrewAI multi-agent crews with production-ready DKIM and 6,000 free sends every month.

Architectural Comparison

SadaSend vs Unchecked SMTP Relays in CrewAI

Why multi-agent AI engineers use SadaSend rather than unmonitored SMTP credentials that risk accidental customer spam.

Feature & CapabilitySadaSendUnchecked SMTP Relays in CrewAI
Human Approval Queue HoldEmails sent immediately with no review
Multi-Agent Loop ProtectionVelocity tripwire halts burstsAgents send infinite emails in loops
Recipient Domain Allowlists
Custom DKIM Signing on Free TierRequires expensive enterprise upgrade
Python Tool Decorator Support
Permanent Free Tier6,000 sends foreverTrial or credit card required
Forever Free Tier
Transparent Economics

Start with 3,000 emails every month at zero cost

No artificial paywalls on security. Unlike legacy providers that reserve recipient allowlists or dedicated IP pools for high enterprise tiers, every SadaSend account receives full safety controls from day one.

3,000 dispatches monthly forever with zero credit card
All safety gates, allowlists, and velocity limits included
Scale seamlessly: Starter ($12/mo for 10k), Pro ($19/mo for 50k), Scale ($79/mo for 250k)
Free Developer Plan
$0 / mo

No credit card required

Create Free AccountCompare all paid plan tiers
Frequently Asked Questions

Everything you need to know about CrewAI email API

Clear, transparent answers on deliverability, API authentication, and rate limits.

When an API key has approval_required enabled, emails dispatched by your CrewAI agent enter a pending state in your SadaSend dashboard. You can inspect the email and approve or reject it before delivery.
Technical Deep Dives

Related developer guides and architectural tutorials

Explore step-by-step production implementation blueprints, benchmarks, and protocols.

Documentation

AI coding agent rules (AGENTS.md, Cursor, Claude)

Setup instructions and rule files for AI coding agents: AGENTS.md, .cursorrules, CLAUDE.md, and hosted MCP configuration.

Read guide
Documentation

REST API Reference & Endpoints

Complete REST API reference for sending emails, managing API keys, tracking delivery events, and configuring recipient allowlists with low latency.

Read guide
Documentation

Model Context Protocol (MCP) Server

Connect AI agents directly to SadaSend via Model Context Protocol (MCP). Inspect tools, configure execution scopes, and enable human approval holds.

Read guide
Deep Dive3 min read

CrewAI Email Dispatcher Agent: Multi-Agent Workflows with Human Sign-Off

CrewAI lets multi-agent swarms collaborate on complex tasks. Learn how to isolate email sending into a dedicated role with human approval gates.

Read tutorial
Deep Dive3 min read

LangChain Email Tool Calling: Safe Integration with Recipient Allowlists

Connecting LangChain agents to raw SMTP credentials risks uncontrolled outbound email. Here is the architectural guide to building safe email tools using Pydantic schemas and scoped credentials.

Read tutorial
Deep Dive3 min read

How to Safely Let Agents Send Email: Defense-in-Depth for Autonomous Outbound

An engineering guide to defense-in-depth for autonomous email: preventing indirect prompt injection, infinite retry loops, and unverified recipient spam.

Read tutorial
Deep Dive5 min read

Preventing Infinite Email Loops in Autonomous AI Agents: Circuit Breakers and Token Buckets

When two autonomous email agents start talking to each other, they can trigger an infinite email loop in minutes. Here is how to engineer circuit breakers, token buckets, and idempotency safeguards.

Read tutorial