> For the complete documentation index, see [llms.txt](https://docs.augelab.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.augelab.com/function-blocks/blocks-reference/input-output/communication/send-mail.md).

# Send Mail

This function block lets you send emails using Gmail SMTP. It is intended for sending plain-text messages and optional file attachments from workflows. The block expects the sender account to be enabled for Gmail API / SMTP access.

## 📥 Inputs <a href="#inputs" id="inputs"></a>

`Subject` - The email subject text (string).

`Content` - The body content of the email (string).

`Sender Address` - The Gmail address that will send the message (string). Must be configured for SMTP/API use.

`Mail API Password` - The password or API key used for authenticating the sender address (string).

`Receiver Address` - The destination email address (string).

`Attachment File Path` - Optional full file path to attach to the email (string). Leave empty if no attachment.

`Trigger` - Boolean signal that initiates sending when active.

## 📤 Outputs <a href="#outputs" id="outputs"></a>

`Success` - Boolean indicating whether the send action succeeded.

## 🕹️ Controls <a href="#controls" id="controls"></a>

`Send` - There is no separate send button; sending is initiated by providing an active `Trigger` to the block. Configure message fields via inputs.

## ⚙️ Running Mechanism <a href="#how-it-runs" id="how-it-runs"></a>

* The block waits for inputs to be provided and for the `Trigger` to become active.
* When triggered, it attempts to authenticate the provided sender account and send the message to the receiver.
* Attachments are included when a valid file path is provided.
* The block returns `Success` True on successful send, False otherwise.
* If authentication or delivery fails due to a transient issue, the block will attempt to reconnect and resend automatically.

## ✨ Features <a href="#features" id="features"></a>

* Sends plain-text emails via Gmail SMTP.
* Supports a single file attachment by file path.
* Uses a cached session to avoid re-authenticating on every trigger when possible.
* Automatic reconnect and retry on transient session issues.

## 📝 Usage Instructions <a href="#usage" id="usage"></a>

1. Provide the sender credentials and enable SMTP/API access on the Gmail account.
2. Fill `Subject`, `Content`, `Sender Address`, `Mail API Password`, and `Receiver Address` inputs.
3. Optionally provide a file path to `Attachment File Path` for attachments.
4. Activate the `Trigger` input to send the message.
5. Monitor the `Success` output to confirm delivery.

## 💡 Tips and Tricks <a href="#tips-and-tricks" id="tips-and-tricks"></a>

* To capture and attach an image from a camera, combine this block with `Camera USB` or `Camera IP (ONVIF)` and save the frame using `Image Write` or `Image Logger`. Provide the saved path to `Attachment File Path`.
* If you want to send notifications only once when an event happens, use `Rising Edge` or `Logic Input` to create a one-time `Trigger` pulse.
* Build message text dynamically using `String Merge` or prepare structured logs with `Data to JSON` before sending.
* When emailing multiple images, use `Multi Image Write` to store images then attach from file paths (one at a time as supported).
* For sending event snapshots as part of analysis pipelines, combine with analysis blocks such as `Find Object` or `Mask Detection` to decide when to trigger the email.

## 🛠️ Troubleshooting <a href="#troubleshooting" id="troubleshooting"></a>

* Authentication fails: verify that the `Sender Address` is enabled for SMTP/API access and that the `Mail API Password` is correct. Check Gmail account security settings.
* Attachment not sent: ensure the path in `Attachment File Path` points to an existing file and is accessible from the runtime environment.
* Email not delivered: check receiver address spelling and spam/junk folders. Network restrictions or firewalls may block SMTP ports.
* Trigger ignored: confirm the `Trigger` input receives an explicit True value (or a rising edge) at runtime.
* Session expired: the block will attempt to reconnect automatically, but if persistent failures occur, re-check credentials and network connectivity.

## 🔒 Privacy & Security <a href="#privacy-and-security" id="privacy-and-security"></a>

* Do not store sensitive passwords in shared projects. Use secure secrets handling where possible.
* Limit the sender account privileges and enable appropriate security measures on the Gmail account used for sending.