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Choose which device events send a text or email

October 9, 2026

In IoT Message, a trigger decides which of your devices' events send a text or an email, and to whom. You can make it as broad as every message, or as narrow as one value from one device.

Which events a trigger looks at

• Where the event came from: a Hologram alert that calls a webhook, a message your device sent to Hologram's cloud, or either.
• What kind of event it is: a device message, a SIM near or over its data limit, a SIM moved to different hardware, the first IMEI seen, an SMS, the result of a message sent to the device, and more.

Conditions

A trigger can have up to 10 conditions, and sends when all of them match, or when any one does. Each condition compares one part of the event:

• the device ID or the device name
• the event's tags
• the Hologram organization
• a value in the message itself, such as temp in {"temp": 41.5}, or the text of a plain message

The comparisons are equals, does not equal, contains, starts with, is greater than, is less than, is present, and is one of a list. They ignore upper and lower case, and "greater than" and "less than" compare numbers.

A few examples:

• Text the night crew when temp is greater than 40 on any freezer tagged cold.
• Email the office when a message contains fault.
• Text the owner when a SIM in one organization is near its data limit.
• Send everyone on a pump's list a text when its level is less than 10.

Who gets it, and how often

• Recipients: everyone you associated with the event's device, or a fixed list. Each person gets a text, an email, or both.
• The words: the trigger's template, with values from the event in it, such as the device name and the reading.
• A cooldown: after an alert, the same trigger waits the minutes you set before it sends again for the same device. A device that switches back and forth between two readings sends one alert in that time. You can turn the cooldown off.
• Late alerts: when an alert cannot go out at once, the trigger says whether to send it when it can, only within some minutes, or not at all.
• More than one trigger: each trigger that matches an event sends its own alert. If two would send the same message to the same person, it goes once.

Starting points, and testing first

The trigger form has five starting points: a device sent something, a message containing certain text, a reading above a number, a SIM near or over its data limit, and a SIM moved to different hardware. Everything it fills in stays editable.

Before you turn a trigger on, you can test it against your recent events. IoT Message shows which ones it would have matched and the message each would have sent, without sending anything.

On paid plans, a trigger can also pause the SIM of the device that sent the event, as well as or instead of sending a message.

The Help page covers what needs a webhook and what needs your Hologram API key, and Pricing lists the plans.