> For the complete documentation index, see [llms.txt](https://help.activenow.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.activenow.io/en/communication/email-not-delivered-to-participant.md).

# Email Not Delivered to a Participant

A participant says they didn't receive an email? The cause depends on what's shown next to their email address and the message status in the communication history.

## A red exclamation mark appears next to the email address

A red exclamation mark means the email address doesn't exist — the message could not be delivered because no mailbox with that address exists. Confirm the correct email address with the participant, update it in their profile, and resend the message.

<figure><img src="/files/FWO63XI4cLxqhWWZNCuE" alt=""><figcaption></figcaption></figure>

## No exclamation mark, message status: Delivery failure

If there's no exclamation mark but the message status is ***Delivery failure***, it means the participant's mailbox is full — the message reached the recipient's server but there was no space to store it. Let the participant know they need to free up space in their inbox.

## No exclamation mark, message status: Delivered

If the status is ***Delivered***, the message reached the recipient's server. If the participant can't find it, ask them to:

* search for the message by sender address: **<hello@activenow.io>**
* check their spam folder


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