Email server monitoring that catches a silent server.

A down mail server doesn't announce itself — receipts, password resets and invoices just quietly stop arriving. Uptimia connects to your SMTP, POP3 and IMAP servers as often as every 30 seconds, confirms the failure from several regions, and pages you long before a customer asks where their receipt went.

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Ships with every uptime monitor · no add-on No credit card GDPR-ready · hosted in Europe
Dead server to alert
30s
Locations to confirm
3
Checkpoints
171+
Countries covered
70+

The night mail stopped moving

The relay accepted its last message at 02:13 and then simply stopped answering. It sent no bounce, logged no error and raised no ticket.

02:14:08 smtp.caldmont.com stops answering on :587The Rotterdam checkpoint catches it on a 30-second check — no alert yet senders warned: none
02:14:15 Toronto and Singapore agreeIncident opens — Slack, SMS and PagerDuty fire seven seconds after the first miss senders warned: none
02:17 On-call acknowledges from the alertOne tap on the signed link — no login mid-incident · MTTA 3 min senders warned: none
02:31 Recovered — with proof attachedServer reply, error class, route — captured at failure time none needed
17 minsilent → fixed
You knew before your senders did.02:31
Caught inside 30 seconds, agreed by three regions seven seconds later, acknowledged within three minutes — and the reply the server gave at failure time rides with the incident, not lost with it.
paged 7 s after the first timeoutacknowledged from the alert, no loginserver reply auto-capturedSlack · SMS · PagerDuty — 12 channels
And without monitoring? A mail server that stops answering sends no bounce and no ticket. You find out when a customer asks where their receipt went — days later, with no reply captured and no idea when it started. no evidence

Every mail port, from outside

Submission, relay and mailbox access — SMTP, IMAP and POP3, encrypted or plain, on the ports your mail actually uses.

SMTP submissionPort 587 · StartTLS
SMTP relay & MXPort 25 · inbound mail
SMTPSPort 465 · implicit TLS
IMAPPort 993 · SSL/TLS
171+ checkpoints over 120 of them open SMTP
POP3Port 995 · SSL/TLS
TLS handshakeCertificate & protocol negotiated
Greeting bannerThe 220 / +OK / * OK reply
Alerts fire on the failure mode, not just "down": a refused connection, a timeout with no answer, a broken TLS handshake — or a greeting that never arrives. not just down

Confirmation, paging and root cause

False-alarm protection

Confirmed before it pages you

One probe failing to reach your mail server never pages you — a single congested route looks like an outage. Uptimia re-tests from the other regions, and the incident opens only once they agree. Recovery is fail-safe — one good connection clears it.

  • Confirmation you set — 1 to 3 independent checkpoints must agree first, default 3
  • One outage, one page — a single incident opens, not a page per checkpoint
  • A delay you choose — how long a failure must persist before anyone is paged
How confirmation works →
🇳🇱Rotterdameu-rtm · 02:14:08timeout
🇨🇦Torontona-tor · 02:14:11timeout
🇸🇬Singaporeap-sin · 02:14:13no banner
3 / 3regions
agree
Incident opened02:14:15
Paged 7 s after the first timeout — confirmed real, not one bad route.
SlackSMSEmailPagerDuty
Only one region can't connect? Re-checked and dismissed — a local network blip never pages you. no alert
Alerting

The right person hears within seconds

A confirmed mail-server failure alerts the channels your team already lives in. If it goes unanswered, the ladder brings in the next person, and a recovery notice closes the loop out.

  • Escalation ladders climb to the next responder — acknowledge with one click, no login
  • Maintenance windows — a planned mail migration never pages anyone
  • Recovery notice with the downtime, sent when the server answers again
How escalation ladders work →
Down confirmed02:14:15
smtp.caldmont.com — alert sent the moment three regions agreed.
SlackSMSEmailPagerDuty+ 8 more
1
First on-call
paged 02:14:15 · Slack, SMS and email
unacknowledged
after 2 min the ladder steps up
2
Second on-call
acknowledged 02:17:04 · one click, no login
MTTA 3 m
step 3
3
Engineering lead
never paged — stays asleep
Recovered 02:31:20 — a recovery notice carrying the total downtime goes to the same channels. Loop closed. down 17 m
Root cause

The reply the server actually sent

Each incident keeps what the failing checkpoints saw on the wire — how the connection broke, the server's own reply and the route to it — so the fix starts from facts, not from reproducing it at 2 a.m.

  • The server's reply and the error class — captured the moment it failed
  • Connection time on every check — stamped with the checkpoint that ran it
  • Hand it over — export to PDF or HTML, or share a public incident link
What every incident records →
DOWNIncident #2571
smtp.caldmont.com:587 · Rotterdam · 02:14:08 UTC
errortimeout
greetingno 220
waited20,000 ms
Expected greeting
220?never received
Server reply captured 
connect OK :587
awaiting 220…
no data · 20s
Traceroute 
9   ae-1.rtm    11 ms
14  be2.par    186 ms
15  * * *      lost
The whole record travels — as a PDF, an HTML file, or a public link anyone opens without a login. 1 click
Global network

Read from where your senders are

Probes on six continents reveal when your mail server refuses a connection from one region but answers fine from another. Use the whole network, or pick the regions your senders live in.

  • Checks as often as every 30 seconds — a dead relay can't hide between checks
  • Every check stamped with its checkpoint — and the log filters by country
  • Every probe IP is published — one allow-list pass through your mail firewall
Where our checkpoints are →
smtp.caldmont.com:587rotating across every region · 02:14 UTC
🇨🇦 Toronto
220 · 41 ms
🇳🇱 Rotterdam
timed out
🇸🇬 Singapore
220 · 63 ms
+ 168 more
watching worldwide
Six locations minimum on any monitor — a mail check can't be narrowed down onto one region's route. min 6

A dead mail server won't warn you.So we will.

SMTP, POP3 and IMAP checks, every region, every alert channel — free for 30 days, and none of it is a paid add-on.

Start your 30-day trial →
30 days free no credit card cancel anytime

How email server monitoring works

Running in under a minute — nothing to install, every check runs from our network.

Step 120 seconds

Point it at your mail server

Protocol, port and encryption come pre-filled — SMTP on 587 with StartTLS, or pick POP3 or IMAP.

Mail server · SMTP / POP3 / IMAP
smtp.caldmont.com:587
SMTP · StartTLS · 220 greeting from eu-rtm in 44 ms
Frequency
Every 30 seconds
Locations
Every probe that allows SMTP
Step 220 seconds

Choose who gets paged

Add the channels and people — escalation ladders and quiet hours are optional.

Notify over
EmailSlackSMSWhatsApp+ PagerDuty, Teams, Telegram…
Alert when
Down · confirmed from 3 regions
CancelStart the check →
Step 3automatic

Get paged when mail stops

One confirmed failure opens a single incident and lights up every channel you chose.

#ops-alerts
Uptimia 02:14
⚠ Down — smtp.caldmont.com
no 220 greetingconfirmed from 3 regions02:14:15 UTC
Also sent to EmailSMSPagerDuty

Also included

Full REST API

Create, pause and clone SMTP, IMAP and POP3 monitors from CI or a script, with per-user keys.

POST /api/v2/uptime → 201 · monit_type: 7 · port: 587

Blacklist monitoring

A reachable relay can still be blocked — watch your sending IPs.

sending IP · 17 DNSBLs · ✓ listed on none

Scheduled reports

Availability and response-time reports, branded with your own logo and colours.

DailyWeeklyMonthly

Public status pages

Tell customers mail is flowing — and post updates when it isn't.

mail status · live · incident updates

Maintenance windows

A planned mail migration never wakes the on-call.

Sat 01:00–03:00 · alerts paused

One dashboard for everything

Your SMTP, IMAP and POP3 checks sit beside web, SSL, DNS and heartbeat monitors — same contacts, groups and roles.

smtp.caldmont.comSMTP imap.caldmont.comIMAP www.caldmont.comUPTIME

Alerts reach whoever is on call

One mail-server incident, fanned out to every channel your team already watches.

On-call & escalation
PagerDuty Webhooks Twilio
Direct
Email SMS

12 channels, one contact list — the people who hear about the website hear about the mail server.

Browse the full integrations directory →
02:14 · incident opened — smtp.caldmont.com · no 220 greeting
#ops-alertsSlack
⚠ Down — smtp.caldmont.com
no 220 greetingconfirmed 3/3 regionsAcknowledge ↩
+371 ··· 4082SMS
Uptimia: DOWN smtp.caldmont.com. No 220 greeting on :587, confirmed from 3 regions at 02:14 UTC.
InboxEmail
⚠ Down — smtp.caldmont.com · no 220 greeting
Confirmed from Rotterdam, Toronto and Singapore at 02:14:15 · acknowledge with one click…
ProductionPagerDuty
TRIGGEREDDown — smtp.caldmont.com
assigned to on-call · via Uptimia integration

What is email server monitoring?

Email server monitoring is an automated check that repeatedly connects to your SMTP, POP3 or IMAP server from outside your network and confirms it accepts the connection and returns a valid greeting — optionally over TLS, and optionally matching a reply you expect. When the connection is refused, times out or the TLS handshake breaks, it alerts you — so a mail server that stops answering is caught in seconds, not days.

While everything works

How does email server monitoring work?

Uptimia
SMTP-capable checkpoints
SMTP check · every 30 s
Your mail server
220 ready · 44 ms

Each check confirms the connection opens, the greeting arrives and — if you set one — an expected reply is present, building your availability and response-time history.

When a check fails

Confirm first, then alert

Your mail server
connection refused
re-checked in 3 regions
Uptimia
raises the incident

confirmed 3/3 → the incident opens and alerts fire

The ports

Which port should I check?

SMTP, IMAP and POP3 each answer on a plain and an encrypted port. Point the monitor at the one your server actually uses, and pick the matching encryption.

See all monitor types →
Protocol & portEncryptionA failed check means
SMTP · 587StartTLSsenders can't hand off outbound mail
SMTPS · 465SSL/TLSimplicit-TLS submission is refused
SMTP relay · 25optionalinbound mail can't reach you
IMAP · 993SSL/TLSusers can't open their mailbox
POP3 · 995SSL/TLSusers can't download their mail

Email server monitoring FAQ

01What is email server monitoring?+
An automated check that connects to your SMTP, POP3 or IMAP server from outside your network and confirms it accepts the connection and answers correctly. It runs as often as every 30 seconds from checkpoints across dozens of countries, agreeing across several regions before it pages you.
02How does the check actually work?+
Each check opens a real connection to the port you specify, reads the server's greeting, and — if you set one — checks the reply contains an expected string, optionally over TLS or StartTLS. A failed connection is re-tested elsewhere; an incident opens only on a confirmed failure, and the first good connection closes it again.
03Does it log in to my mailbox or send a test email?+
No. It confirms the server is reachable and answers correctly from the outside — it does not sign in to a mailbox or send mail through your server. That keeps the check safe to run every 30 seconds and means you store no mailbox password with us. To watch whether your sending IPs are being blocked, pair it with blacklist monitoring.
04Which protocols and ports can it check?+
SMTP (25, 465 or 587), POP3 (110 or 995) and IMAP (143 or 993). Pick the protocol and port your server uses, then toggle StartTLS for SMTP submission or SSL/TLS for POP3 and IMAP.
05What counts as "down" for a mail server?+
A refused connection, a timeout with no answer, a broken TLS handshake, or a greeting that doesn’t contain the reply you asked for. The last one is yours to opt into — set an expected reply and a wrong answer counts as down; leave it blank and only the connection itself has to succeed.
06What information do I get when a check fails?+
Which checkpoints failed and when, the error class (connection, timeout, TLS or missing reply), the server’s captured reply, and the traceroute to it. Export any incident to PDF or HTML, or share it as a public link.
07How is this different from port monitoring?+
It is the same reliable connection check, pre-set for mail: the mail ports, the right encryption label, and an optional greeting match. A generic TCP port monitor does the same thing without the mail-oriented defaults.
08Can it check encrypted connections?+
Yes. Turn on StartTLS for SMTP submission, or SSL/TLS for SMTPS, IMAP over 993 and POP3 over 995 — the check fails if the handshake breaks or the certificate can't be negotiated.
09How do I get alerted when mail stops?+
Over the same 12 channels every monitor uses — Slack, Teams, Discord, Mattermost, Telegram and WhatsApp for chat; PagerDuty, Twilio and webhooks for on-call; plus email, SMS and Atlassian Statuspage. Nobody acknowledges? The ladder climbs to the next person, and one signed-link click clears it — no login.
10Is there a free plan?+
Yes — email server checks are part of the uptime monitor family on every plan, never a paid add-on. The free plan watches one server on 5-minute checks, no card, commercial use welcome; Basic raises that to 10 monitors, Professional to 100 with 30-second intervals, and plans go up to 1,000. The 30-day trial opens everything, with room for 500 monitors.
11Can every checkpoint check an SMTP server?+
No, and it is worth knowing why. Many hosting providers block outbound SMTP from their networks to stop spam, so a little under a third of our checkpoints cannot open a connection to port 25, 465 or 587 at all. An SMTP monitor is scheduled only on the checkpoints that can — over 120 of them, spread across more than fifty countries. POP3 and IMAP monitors are unaffected and run on the whole network. If you pin an SMTP monitor to particular regions rather than using every probe, choose regions where SMTP is allowed, or the check will run from fewer places than you picked.

Start watching your mail server today.

Point it at your SMTP, POP3 or IMAP server — be the first to know when mail stops flowing.

Monitor your mail server →
30-day free trial 500 monitors included No credit card EU-hosted, GDPR-ready
Email server checks are part of uptime monitoring — included in every Uptimia plan.