How to Set Up IMAP Uptime Monitoring

What is an IMAP Check?

An IMAP check connects to your mail server from Xitoring's global probing nodes and verifies that the IMAP service is responding with a valid greeting. IMAP is what your email clients (Outlook, Apple Mail, Thunderbird) use to read mail from a server, so an IMAP outage means inboxes stop loading even if mail is still being delivered.

Use IMAP checks for:

Self-hosted mail servers (Dovecot, Cyrus, Courier)
Hosted mailboxes you operate for staff or customers
Mail relays that expose IMAP to end users
Migration cutovers — verify the new IMAP target is up before flipping DNS

What Gets Monitored

Connection success — TCP handshake on the IMAP port
Greeting / capability response — server returns a valid IMAP greeting (e.g., * OK IMAP4rev1)
TLS handshake when monitoring IMAPS (port 993)
Response time — time to greeting from each probing node
Geographic availability — reachable from each region

Prerequisites

A reachable mail server hostname or IP
The IMAP port in use:
- 143 — plain IMAP (with optional STARTTLS)
- 993 — IMAPS (implicit TLS)
Firewall rules allowing TCP from Xitoring's probing IP ranges
A valid TLS certificate when monitoring IMAPS

How to Set Up an IMAP Check

Step 1: Create the Check

Log in to your Xitoring Dashboard
Go to Uptime → Add Check
Select IMAP as the check type

Step 2: Configure the Connection

Enter the hostname (e.g., imap.example.com)
Set the port — 143 for plain, 993 for IMAPS
Enable SSL/TLS if monitoring port 993
Optionally set an expected greeting substring (e.g., * OK)
Set the check interval (30 seconds to 15 minutes)
Set the timeout (default: 30 seconds)

Step 3: Choose Probing Nodes

Select at least 3 probing nodes across the regions where your mail users connect from.

Step 4: Assign Notifications

Under Triggers, attach a notification role — IMAP outages affect every email client, so route alerts to a channel that gets seen quickly.

Step 5: Save and Verify

Save the check. The first probe runs immediately.

Setting Up Triggers

Common alerting rules:

Connection refused or timed out — IMAP daemon down or port blocked
Greeting mismatch — wrong server responding or service misconfigured
TLS handshake failure — expired or invalid certificate on 993
Slow response — exceeds your threshold (IMAP should respond in well under a second)

Tips

Monitor both ports if you support legacy clients — 143 for plain/STARTTLS and 993 for IMAPS
Pair with SSL certificate monitoring on the mail hostname to catch certificate expiry before clients break
Watch response time — slow IMAP usually means the mail store is overloaded, which often precedes downtime
Test from the regions your users actually live in — international staff may be hitting the server through different network paths
Don't expose IMAP without TLS to the public internet — STARTTLS on 143 or implicit TLS on 993 is the bare minimum