Published 9 September 2026 · Managed services · Nagios
An MSP in the Midwest manages infrastructure for several client businesses. Nagios monitors the client environments and sends an alert email when a host or service check fails. Until recently, those emails went to a shared inbox that nobody watched overnight.
That was the whole problem. An alert that arrived at 3 a.m. was read at 8 a.m., when the first technician sat down. Whatever Nagios had found in between waited, unread, with nobody accountable for noticing it.
Why Not Just Watch the Inbox?
Because nobody can, not reliably and not every night. A shared mailbox has no way to wake anyone up. An email notification at 3 a.m. looks like every other notification on a phone, and a small MSP does not have a night desk.
The team did not need an incident platform with rotations and dashboards. They needed one thing: for a phone to ring when Nagios raised a critical alert, and for the call to come back if nobody picked up.
How It Is Set Up
| Sending tool | Nagios. The notification contact's email address is the MSP's Email2Phone address, name@email2phone.net. |
|---|---|
| Filter | One condition: Subject contains CRITICAL. Action: Call the technician's mobile. |
| Acknowledgement | The technician presses 8 to save the message once heard. On a phone with voicemail switched off, Email2Phone calls back at 5, 15, 30, 60 and 60 minutes until someone presses a key. |
| Plan | Basic, $10 a month for 40 credits. In a typical month the account uses fewer than 10 alert calls. |
What Happens at 3 a.m. Now
Nagios detects a failed check and emails the alert, as it always did. The email lands at the Email2Phone address. The filter matches the word CRITICAL in the subject and rings the technician's mobile.
The technician answers, presses 1, and hears the message read aloud: the subject line first, then the body, exactly as Nagios wrote it. They press 8 to save it, which acknowledges it. Pressing 7 to delete or 5 to record a spoken reply counts as acknowledgement too. If they want to hear the details again once they are at a laptop, they can dial in free from a US, Canadian or UK number and replay it.
If the call goes unanswered on a phone with voicemail switched off, Email2Phone calls back five minutes later, then at 15, 30, 60 and 60 minutes; had voicemail picked up, the message would have been left there and counted as delivered, with no callbacks. A message is only acknowledged when someone presses a key. After the fifth attempt it is filed in the account's online Message History, but by then the phone has rung again and again for close to three hours.
Because Nagios sends recoveries and warnings by email too, the filter matters. Only subjects that contain CRITICAL ring the phone. The rest stay out of the call queue, which keeps the night quiet for anything that can wait until morning.
Why It Fits an MSP
The MSP already had the monitoring. What Nagios lacked was the last step: a way to put a critical alert in front of a human at night. Email2Phone added that step without changing anything about how Nagios works. One contact address changed, one filter added.
The cost follows the volume. At fewer than 10 alert calls a month, the account sits inside the $10 Basic plan with credits to spare. The plan is priced on credits, one credit for up to 60 seconds of call to a US or Canadian number, not on seats, so it does not grow with the number of technicians.
And it works on whichever phone the MSP points the filter at. Handing the night alerts to a different technician means changing the number the filter calls. There is no app to install on the new handset.
What It Does Not Do
Email2Phone is not an incident manager. It does not keep an on-call schedule, build a timeline or report response times. For this MSP, none of that was part of the requirement. The requirement was that a phone rings when Nagios says CRITICAL, and rings again if nobody answers.
Get a Phone Call When a Critical Email Arrives
If your monitoring alerts land in an inbox nobody reads at night, the setup can be as small as one address and one filter. See how email to phone call alerting works for an MSP, check the Nagios setup, or start a free 30-day trial with no credit card.
This case study is based on a real customer account, anonymised to protect their privacy.