SMTP Monitor
The SMTP Monitor verifies that your SMTP server is reachable and responsive. This helps you detect outages of outbound mail gateways and mail delivery infrastructure before users report missing emails.
How it works
- We connect to your SMTP server and validate that it responds as expected.
- If the server cannot be reached or does not respond in time, we mark the check as failed.
Configuration
Basic settings
- Hostname: Hostname only, without protocol or path.
- Port: Optional. Use your SMTP port (commonly 25 / 587 / 465).
- Check interval and Timeout.
- Status:
active,maintenance,disabled.
Advanced settings
Depending on your use case, advanced options (e.g. encryption/auth requirements) can be configured via the monitor settings.
Monitoring locations
SMTP checks run from our monitoring locations. You can restrict execution using Allowed Check Countries (monitor-level) or by using the customer-level defaults.
Port-only mode (no credentials)
By default (Check Mode: protocol), the monitor connects to your SMTP server and validates that it responds as expected. Set Check Mode to tcp to skip that protocol validation. The monitor only opens a bare TCP connection to hostname:port, without any SMTP handshake, and no credentials are required or stored. Use tcp mode when you only need to confirm the port is reachable.
ICMP Monitor
The ICMP Monitor checks whether a host is reachable on the network. This is ideal for infrastructure components that do not expose HTTP endpoints (e.g. routers, firewalls, VPN gateways, databases, or internal services).
SSH Monitor
The SSH Monitor checks whether your SSH service is reachable. It is commonly used to detect firewall issues, network outages, or server crashes affecting administrative access.