# Missing notifications for read messages

Source: https://developer.nylas.com/docs/support/troubleshooting/missing-webhook-notifications/

Sometimes, you might not receive [`message.opened` webhook notifications](/docs/v3/email/message-tracking/#message-open-tracking) when a recipient has read a message.

Nylas detects that a message has been read by embedding a single-pixel image file in the message HTML and tracking when that image is downloaded. Nylas tracks the initial download only.

Nylas might not generate `message.opened` webhook notifications for any of the following reasons:

- The email client reads text-based messages only, and doesn't accept HTML. This means the single-pixel image file is never downloaded.
- The email client strips attachments and replaces them with literal HTML that represents the file name (for example, `<spacer.gif>` might be appended to the message).
- The email client strips image files from HTML messages.
- The email client doesn't allow image files to be downloaded.

## Solution

In this case, you must contact the recipient and verify that their email client allows them to receive images in messages.

As a work-around, you can also combine Message Open tracking with [Link Clicked tracking](/docs/v3/email/message-tracking/#link-clicked-tracking) to determine that messages have been opened after recipients click an embedded link.

## Resources

For more information about message tracking and the webhooks Nylas generates, see the following documentation:

- [Gmail blog: Images now showing](https://gmail.googleblog.com/2013/12/images-now-showing.html)
- [Message tracking](/docs/v3/email/message-tracking/)
- [Message tracking webhook notification schemas](/docs/reference/notifications/#message-tracking-notifications)
- [Troubleshooting: Immediate webhook notifications for read messages](/docs/support/troubleshooting/immediate-webhook-notification/)