TRUSTED SINCE 2018 • 10,000+ BUSINESSES WORLDWIDE

Round-trip SMTP Monitoring For Businesses That Depend on Email

Small email delays can be costly for your business. MailFlowMonitoring provides round-trip SMTP and IMAP monitoring, continuously testing your email infrastructure by sending test emails and tracking responses. Detect deliverability issues, server outages, and routing problems before they impact your users and customers.

Real-time Monitoring Second-by-second updates
99.9% Uptime Enterprise reliability
Instant Alerts Multi-channel notifications
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No credit card required • Setup in under 10 minutes • First monitor free

Trusted by leading enterprises worldwide

Airbus
Allstate
Amazon
Baker Hughes
Bayer
Capital One
CrowdStrike
Disney
DuPont
EY
FedEx
GSK
Hilton
Merck
Nissan
Pfizer
State Farm
Target
Thomson Reuters

...teams at fast-growing SaaS companies

Datadog
HubSpot
Intercom
PagerDuty
Shopify
Stripe
Twilio
Zendesk

...and state & local governments

City of Chicago
City of Los Angeles
City of New York
State of California
State of Florida
State of Texas

How Round-trip Monitoring Works

Continuous testing ensures your email infrastructure is always operational

1

We Send Test Emails

Our monitoring endpoints continuously send test emails to addresses you specify in your domain, simulating real email traffic.

2

Your Server Auto-Responds

Configure your SMTP server to automatically respond to our test emails. We track response times and delivery success.

3

Instant Alerts on Issues

If responses fail or exceed your configured thresholds, we immediately alert you via email, SMS, webhook, or PagerDuty.

What Round-trip Monitoring Validates

  • MX records are correctly configured for your SMTP servers
  • SMTP servers and relay software are up and running
  • Internet connection is active (for self-hosted or co-located servers)
  • Spam filters are not delaying or blocking legitimate email delivery
  • Complete email routing path is functioning correctly

Monitor Your Mail Flow

Round-trip SMTP and IMAP monitoring with performance metrics and header analysis

Round-trip Email Tests

Continuous inbound and outbound email tests with complete header analysis and transaction logging.

Multi-channel Alerts

Configurable real-time alerts via email, SMS, webhook, PagerDuty, and Slack when thresholds are exceeded.

Performance Metrics

Track response times, delivery success rates, and historical statistics to optimize mail server performance.

Customizable Timeouts

Configure monitoring intervals and timeout thresholds based on your specific business requirements.

Transaction Logging

Complete log of all test emails sent and received, helping diagnose routing and blacklisting issues.

24/7 Monitoring

Day and night continuous testing ensures you're alerted to disruptions the moment they happen.

See It In Action

Explore the intuitive dashboard and powerful monitoring features

MailFlowMonitoring Dashboard

Monitoring Dashboard

Real-time status of all your email servers

Create New Monitor

Monitor Creation

Easy setup wizard for new monitors

Individual Monitoring Statistics

Performance Statistics

Detailed round-trip time metrics

Monitoring Ping Schedule

Ping Schedule

Configurable monitoring intervals

Email Routing Hops

Email Routing Hops

Track the complete email path

Notification Policy Configuration

Notification Policy

Multi-channel alert configuration

Built by Email Infrastructure Experts

As an email service provider, we needed to track mail flow problems through a large number of inbound email servers. Unlike services that deliver to a single MX record, we needed to specify individual IP addresses for message delivery.

We found existing services charging $500+ per month with limited flexibility. So we built our own solution. Since launching in 2018, MailFlowMonitoring has grown to serve over 10,000 businesses worldwide, running millions of monitoring tests every month.

We built the tool we wanted to use ourselves, with the alerting integrations modern teams need: email, SMS, webhooks, PagerDuty, and Slack. Whether you're monitoring a single mail server or complex multi-server infrastructure, we have a plan that fits.

Our Mission: Provide enterprise-grade email monitoring that's accessible to businesses of all sizes. From startups to enterprises, we help teams ensure their email infrastructure is always operational.

Our Email Infrastructure Suite

AutoSPF Automatic SPF record management that stays under the 10 DNS lookup limit DMARC Report DMARC monitoring and reporting to protect your domain from spoofing Phish Protection Advanced email security to block phishing and malware threats Outbound SMTP Reliable SMTP relay service for transactional and marketing email Tenant Migration Seamless Microsoft 365 tenant-to-tenant migration services Inbox Issue Email deliverability diagnostics and inbox placement testing

You're in Complete Control

Scalable Monitoring

Start with one free monitor and scale up as your infrastructure grows. Plans for every team size.

Custom Intervals

Control how often we check your servers, from every minute to hourly intervals.

Flexible Thresholds

Set Round Trip Time thresholds and Notification Delay Rates that match your requirements.

Multi-channel Alerts

Email, SMS, webhook, PagerDuty, Slack - configure alerts through any channel for each monitoring policy.

Start Monitoring Your Email Infrastructure

Join thousands of businesses ensuring their email reliability. Setup takes less than 10 minutes.

Create Your Account

No credit card required • First monitor free • Upgrade anytime