--- title: Mailhook-triggered AI agent slug: mailhook-triggered-ai-agent image: https://archbee-image-uploads.s3.amazonaws.com/oAyFj2GHlBeBVWF5OAir2/0hwqpiYZYkB8ltittUnBp_triggers-1.png docTags: createdAt: 2026-03-19T11:05:57.391Z --- This mailhook-triggered AI agent scenario watches for new emails, and the agent replies to them. Mailhooks (email webhooks) immediately trigger scenarios in response to new emails, rather than [on a schedule](docId\:SclqhRvEy8NQgRTM5AMnP). ![](https://api.archbee.com/api/optimize/oAyFj2GHlBeBVWF5OAir2/qGNDOupP6qFeiew9ABCTg_mailhook-triggered-ai-agent.png) ## Prerequisites - Two email accounts, such as a business email address and a personal email address **This example uses Gmail.** If you have a different email provider, see its documentation for equivalent settings in the relevant steps. ## Step 1. Add a Custom mailhook module The **Webhooks **> **Custom mailhook **module generates an email address (mailhook) that your email provider forwards new emails to, triggering the scenario. To add a **Custom mailhook **module: ::::WorkflowBlock :::WorkflowBlockItem In the Scenario Builder, in the top-left corner, name your scenario and click **Save**. ::: :::WorkflowBlockItem Click the giant plus. ::: :::WorkflowBlockItem In the app search, search for and click **Webhooks**. ::: :::WorkflowBlockItem Select the **Custom mailhook** module. ::: :::WorkflowBlockItem In the module settings, in **Mailhook**, click **Add**. ::: :::WorkflowBlockItem In **Webhook name**, name the mailhook. For example, use the scenario name. ::: :::WorkflowBlockItem Click **Save**. You'll now see the generated mailhook to use in later steps. ::Image[]{src="https://api.archbee.com/api/optimize/oAyFj2GHlBeBVWF5OAir2/_8Wzdo8HuFT2alJxIZ-mV-20260310-151201.png" size="70" width="558" height="419" position="center" darkWidth="558" darkHeight="419" showCaption="false"} ::: :::WorkflowBlockItem Copy the address to your clipboard and click **Save**. You'll later update your email settings to forward emails to it. ::: :::WorkflowBlockItem Click **Save **in the Scenario toolbar. ::: :::: You've now added a **Webhooks **> **Custom mailhook **module. ## Step 2. Add your mailhook as a forwarding email In the email account where new emails trigger the scenario, add the mailhook as a forwarding address so your email provider sends new emails to it. To add the mailhook as a forwarding address: ::::WorkflowBlock :::WorkflowBlockItem Open your Gmail account. ::: :::WorkflowBlockItem Click the **Settings **icon in the top-right menu, and click **See all settings**. ::: :::WorkflowBlockItem Go to the **Forwarding and POP/IMAP** tab. ::: :::WorkflowBlockItem Click **Add a forwarding address**. ::: :::WorkflowBlockItem Paste the mailhook that you copied earlier. ::: :::WorkflowBlockItem Agree to proceed in all remaining steps. ::: :::: You've now added the mailhook as a forwarding address in Gmail. ## Step 3. Create an email filter To send only specific incoming emails to the mailhook, rather than all emails, create a filter in Gmail. To create an email filter: :::::WorkflowBlock :::WorkflowBlockItem In **Settings **in your Gmail account, go to the **Filters and Blocked Addresses** tab. ::: :::WorkflowBlockItem Click **Create a new filter**. ::: ::::WorkflowBlockItem In **From**, enter the email address associated with the email account that you're in now. :::hint{type="info"} Use your own email address so you can send yourself an email and reply to it. Your email reply passes an important header into Make called `references` that you must map later in the scenario. ::: :::: :::WorkflowBlockItem Click **Create filter**. ::: :::WorkflowBlockItem Select **Forward it to: **and select the mailhook that you added in the previous step. ::Image[]{src="https://api.archbee.com/api/optimize/oAyFj2GHlBeBVWF5OAir2/vi30Xf7yw6_bx_nXKy5BV-20260311-150732.png" size="70" width="806" height="639" position="center" darkWidth="806" darkHeight="639" showCaption="false"} ::: :::WorkflowBlockItem Click **Create filter**. ::: ::::: You've now created an email filter, so only specific emails go to the mailhook. ## Step 4. Send a test email to the Custom mailhook module To test that your **Custom mailhook** module receives forwarded emails from Gmail: ::::WorkflowBlock :::WorkflowBlockItem In the Scenario Builder, click **Run once** on the Scenario toolbar. ::: :::WorkflowBlockItem In Gmail, send yourself an email. ::: :::WorkflowBlockItem Once the mailhook receives the email, you can click the output bubble of the **Custom mailhook **module to view the email properties, such as headers. ::: :::: You've now sent a test email to yourself. Next, reply to it. ## Step 5. Reply to the test email Reply to the first test email to pass headers that are only available in email replies —`in-reply-to` and `references`—into the scenario for mapping. You'll need these values for replying to emails. To reply to the test email: ::::WorkflowBlock :::WorkflowBlockItem Click **Run once** on the Scenario toolbar. ::: :::WorkflowBlockItem Go to your Gmail account. ::: :::WorkflowBlockItem Reply to the email that you sent yourself. ::: :::WorkflowBlockItem Once the mailhook receives the email, click the output bubble to expand `Headers` and view the values you'll use in later steps: - `message-ID`: The unique ID of an email - `in-reply-to`: The message ID of the email being replied to - `references`: A list of message IDs in a single thread of emails, with the first ID being the initial email ::: :::: The **Webhooks **> **Custom mailhook** is complete now that it has reply email output data. ## Step 6. Add a Run an agent module To add the **Make AI Agent (New)** > **Run an agent **module: :::::WorkflowBlock :::WorkflowBlockItem Click the plus icon next to the **Webhooks **> **Custom mailhook **module. ::: :::WorkflowBlockItem In the app search, search and click **Make AI Agent (New)**. ::: :::WorkflowBlockItem Click the **Run an agent** module. ::: ::::WorkflowBlockItem In **Connection**, select an existing AI provider connection from the dropdown or click **Add **to add a new one. :::hint{type="info"} If you don't want to create an account with an AI provider, select **Make's AI Provider**. ::: :::: :::WorkflowBlockItem In **Model**, select a model from your chosen AI provider. ::: :::WorkflowBlockItem In **Instructions**, describe who the agent is and what it does. Alternatively, copy-paste the following: You are a helpful agent who replies to emails. ::: ::::WorkflowBlockItem In **Input**, tell the agent to read the email content and answer in HTML. You can copy-paste the following: Read the content of this email \ Text \, and answer in HTML format. Directly reply to the email. Don't add any internal instructions or provide an email signature. :::hint{type="info"} While optional, XML tags (\) clearly separate data (`Text`) from the rest of the instructions. ::: :::: :::WorkflowBlockItem Replace Text with the `Text` value from the **Webhooks** > **Custom mailhook** module. ::Image[]{src="https://api.archbee.com/api/optimize/oAyFj2GHlBeBVWF5OAir2/LqdAYMZaecRD0SbybR8XS-20260312-124822.png" size="60" width="343" height="191" position="flex-start" darkWidth="343" darkHeight="191" showCaption="false"} ::: ::::WorkflowBlockItem In **Conversation ID**, enter the following function: `ifempty(` `first(` `split(` Headers: references`;` `space` `)` `)` `;` Headers: message-id`)` :::hint{type="info"} This function uses the first message ID listed in the `reference` header, and if empty, uses the `message ID`. The` split(`splits the reference array into individual values and the `first(` uses the first value. ::: :::: :::WorkflowBlockItem Replace the text in the function (Headers: reference and Headers: message-id) with the corresponding values from the **Webhooks **> **Custom mailhook** module. ::Image[]{src="https://api.archbee.com/api/optimize/oAyFj2GHlBeBVWF5OAir2/7EdO6nIaT2bTJgWMtlnA2-20260312-132350.png" size="70" width="527" height="236" position="center" darkWidth="527" darkHeight="236" showCaption="false"} ::: :::WorkflowBlockItem Click **Save **in the Scenario toolbar. ::: ::::: You've now added a **Run an agent **module. ## Step 7. Add a Send an email module The **Gmail **> **Send an email **module replies to emails with agent-generated answers from the **Make AI Agent (New)** >** Run an agent **module. To add a **Send an email **module: ::::WorkflowBlock :::WorkflowBlockItem Click the plus icon next to the **Make AI Agent (New) **> **Run an agent** module. ::: :::WorkflowBlockItem In the app search, search for **Gmail **and click** Send an email**. ::: :::WorkflowBlockItem In the module settings, in **Connection**, select the Gmail connection that you used to create the mailhook. ::: :::WorkflowBlockItem In **To**, map the `Sender: Email address` value from the **Webhooks **>** Custom mailhook** module. ::: :::WorkflowBlockItem In **Subject**, map the `Subject` value from the **Webhooks **> **Custom mailhook **module. ::: :::WorkflowBlockItem In **Body type**, select `Raw HTML` because you requested HTML in the agent instructions. ::: :::WorkflowBlockItem In **Content**, map the `Response`value from the **Make AI Agent (New)** > **Run an agent** module. ::: :::WorkflowBlockItem Toggle **Advanced settings**. ::: :::WorkflowBlockItem In **Additional email headers**, add these email headers: - **Email header 1**: - In **Key**, enter in-reply-to. - In **Value**, map the `Headers: message-id` value from the **Webhooks** > **Custom mailhook** module. - **Email header 2**: - In **Key**, enter references. - In **Value**, map the `Headers: references` and `Headers: message-id` values from the **Webhooks **> **Custom mailhook** module. ::Image[]{src="https://api.archbee.com/api/optimize/oAyFj2GHlBeBVWF5OAir2/dS3uBwLPQ-aP1j1m_oVYQ-20260312-154447.png" size="60" width="534" height="638" position="center" darkWidth="534" darkHeight="638" showCaption="false"} ::: :::WorkflowBlockItem Click **Save**. ::: :::WorkflowBlockItem Click **Save **on the Scenario toolbar. ::: :::: Your email webhook-triggered AI agent scenario is now ready to test again. ## Step 8. Update the email filter and test it Based on your current email settings, Gmail forwards emails from yourself—including agent replies to them—to the mailhook. To prevent an infinite loop, where each agent reply triggers the scenario, add a different email address to your email filter, such as your personal email address, and test it from that account. To update the email filter and test it: ::::WorkflowBlock :::WorkflowBlockItem In Gmail, click the **Settings **icon, and click **See all settings**. ::: :::WorkflowBlockItem Click **Filters and Blocked Addresses**. ::: :::WorkflowBlockItem Find your existing email filter and click **edit**. ::: :::WorkflowBlockItem In **From**, add a different email address. ::: :::WorkflowBlockItem Click **Continue**, then click **Update filter**. ::: :::WorkflowBlockItem In the email account associated with the new address, send an email to the original email address. ::: :::WorkflowBlockItem In the Scenario Builder, click **Run once **on the Scenario toolbar to test if agent replies work. ::: :::WorkflowBlockItem Return to the account associated with the new email address. You now have an email thread with the initial email (**1**) and the agent reply (**2**). ![](https://api.archbee.com/api/optimize/oAyFj2GHlBeBVWF5OAir2/ylyWdD7SlpHm8HeC0VD9w-20260313-094129.png) ::: :::: You've now created a mailhook-triggered AI agent scenario, where your target email account forwards emails to a mailhook, and the agent immediately replies to them. Next, you can tailor the email filter with additional specifics, depending on your use case.