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Agent Mail Messages

Blocks for sending, receiving, replying to, forwarding, and managing email messages via AgentMail. Messages are individual emails within conversation threads.

Agent Mail Forward Message

What it is

Forward an email message to one or more recipients. Supports CC/BCC and optional extra text or subject override.

How it works

The block validates that the combined recipient count across to, cc, and bcc does not exceed 50, then calls the AgentMail API to forward a specific message from your inbox. You provide the inbox ID and message ID to identify the original email, along with the target email addresses. Optionally, you can override the subject line or prepend additional plain text or HTML content before the forwarded message body.

The API handles constructing the forwarded email with the original content included. Any errors from the API propagate directly to the global error handler without being caught by the block.

Inputs

Input
Description
Type
Required

inbox_id

Inbox ID or email address to forward from

str

Yes

message_id

Message ID to forward

str

Yes

to

Recipient email addresses to forward the message to (e.g. ['user@example.com'])

List[str]

Yes

cc

CC recipient email addresses

List[str]

No

bcc

BCC recipient email addresses (hidden from other recipients)

List[str]

No

subject

Override the subject line (defaults to 'Fwd: ')

str

No

text

Additional plain text to prepend before the forwarded content

str

No

html

Additional HTML to prepend before the forwarded content

str

No

Outputs

Output
Description
Type

error

Error message if the operation failed

str

message_id

Unique identifier of the forwarded message

str

thread_id

Thread ID of the forward

str

result

Complete forwarded message object with all metadata

Dict[str, Any]

Possible use case

  • Escalation Routing — Forward messages that match certain keywords or priority levels to a human supervisor's email for review.

  • Multi-Agent Collaboration — Forward incoming requests to a specialized agent's inbox so the right agent handles each task.

  • Digest Distribution — Forward summarized daily reports from an aggregation inbox to a distribution list of stakeholders.


Agent Mail Get Message

What it is

Retrieve a specific email message by ID. Includes extracted_text for clean reply content without quoted history.

How it works

The block fetches a single message from an AgentMail inbox by calling the API with the inbox ID and message ID. It returns the full message content including subject, plain text body, HTML body, and all metadata.

A key output is extracted_text, which contains only the new reply content with quoted history stripped out. This is especially useful when feeding message content into an LLM, since it avoids processing redundant quoted text from earlier in the conversation.

Inputs

Input
Description
Type
Required

inbox_id

Inbox ID or email address the message belongs to

str

Yes

message_id

Message ID to retrieve (e.g. 'abc123@agentmail.to')

str

Yes

Outputs

Output
Description
Type

error

Error message if the operation failed

str

message_id

Unique identifier of the message

str

thread_id

Thread this message belongs to

str

subject

Email subject line

str

text

Full plain text body (may include quoted reply history)

str

extracted_text

Just the new reply content with quoted history stripped. Best for AI processing.

str

html

HTML body of the email

str

result

Complete message object with all fields including sender, recipients, attachments, labels

Dict[str, Any]

Possible use case

  • Intent Classification — Retrieve a message and pass its extracted text to an LLM to classify the sender's intent before routing to the appropriate workflow.

  • Conversation Context Loading — Fetch a specific message to build context for generating a relevant reply in a multi-turn email conversation.

  • Attachment Processing — Retrieve a message's full metadata to extract attachment URLs for downstream processing like document parsing or image analysis.


Agent Mail List Messages

What it is

List messages in an AgentMail inbox. Filter by labels to find unread, campaign-tagged, or categorized messages.

How it works

The block queries the AgentMail API to retrieve a paginated list of messages from the specified inbox. You can control the page size with limit (1-100) and navigate through results using the page_token returned from a previous call. An optional labels filter returns only messages that have all of the specified labels.

The block outputs the list of message objects, a count of messages returned in the current page, and a next_page_token for fetching subsequent pages. When next_page_token is empty, there are no more results.

Inputs

Input
Description
Type
Required

inbox_id

Inbox ID or email address to list messages from

str

Yes

limit

Maximum number of messages to return per page (1-100)

int

No

page_token

Token from a previous response to fetch the next page

str

No

labels

Only return messages with ALL of these labels (e.g. ['unread'] or ['q4-campaign', 'follow-up'])

List[str]

No

Outputs

Output
Description
Type

error

Error message if the operation failed

str

messages

List of message objects with subject, sender, text, html, labels, etc.

List[Dict[str, Any]]

count

Number of messages returned

int

next_page_token

Token for the next page. Empty if no more results.

str

Possible use case

  • Inbox Polling — Periodically list messages labeled "unread" to trigger automated processing workflows for new incoming emails.

  • Campaign Monitoring — Filter messages by campaign-specific labels to track reply rates and engagement across an outreach sequence.

  • Batch Processing — Page through all messages in an inbox to perform bulk operations like summarization, archiving, or data extraction.


Agent Mail Reply To Message

What it is

Reply to an existing email in the same conversation thread. Use for multi-turn agent conversations.

How it works

The block sends a reply to an existing message by calling the AgentMail API with the inbox ID, the message ID being replied to, and the reply body text. An optional HTML body can be provided for rich formatting. The API automatically threads the reply into the same conversation as the original message.

The block returns the new reply's message ID, the thread ID it was added to, and the complete message object. This makes it straightforward to build multi-turn email conversations where an agent responds to incoming messages within the same thread.

Inputs

Input
Description
Type
Required

inbox_id

Inbox ID or email address to send the reply from

str

Yes

message_id

Message ID to reply to (e.g. 'abc123@agentmail.to')

str

Yes

text

Plain text body of the reply

str

Yes

html

Rich HTML body of the reply

str

No

Outputs

Output
Description
Type

error

Error message if the operation failed

str

message_id

Unique identifier of the reply message

str

thread_id

Thread ID the reply was added to

str

result

Complete reply message object with all metadata

Dict[str, Any]

Possible use case

  • Customer Support Agent — Automatically reply to incoming support emails with answers generated by an LLM based on the message content and a knowledge base.

  • Interview Scheduling — Reply to candidate emails with proposed interview times after checking calendar availability through another block.

  • Conversational Workflow — Maintain an ongoing back-and-forth conversation with a user, where each reply builds on the previous exchange to complete a multi-step task.


Agent Mail Send Message

What it is

Send a new email from an AgentMail inbox. Creates a new conversation thread. Supports HTML, CC/BCC, and labels.

How it works

The block first validates that the combined count of to, cc, and bcc recipients does not exceed 50. It then calls the AgentMail API to send a new message from the specified inbox, creating a new conversation thread. You must provide at least a plain text body; an optional HTML body can be included for rich formatting.

The block supports CC and BCC recipients for human-in-the-loop oversight or silent monitoring, and labels for tagging outgoing messages for later filtering. The API returns the new message's ID, the thread ID for tracking future replies, and the complete message object.

Inputs

Input
Description
Type
Required

inbox_id

Inbox ID or email address to send from (e.g. 'agent@agentmail.to')

str

Yes

to

Recipient email addresses (e.g. ['user@example.com'])

List[str]

Yes

subject

Email subject line

str

Yes

text

Plain text body of the email. Always provide this as a fallback for email clients that don't render HTML.

str

Yes

html

Rich HTML body of the email. Embed CSS in a

str

No

cc

CC recipient email addresses for human-in-the-loop oversight

List[str]

No

bcc

BCC recipient email addresses (hidden from other recipients)

List[str]

No

labels

Labels to tag the message for filtering and state management (e.g. ['outreach', 'q4-campaign'])

List[str]

No

Outputs

Output
Description
Type

error

Error message if the operation failed

str

message_id

Unique identifier of the sent message

str

thread_id

Thread ID grouping this message and any future replies

str

result

Complete sent message object with all metadata

Dict[str, Any]

Possible use case

  • Outreach Campaigns — Send personalized cold emails to a list of prospects with campaign labels for tracking, using HTML templates for professional formatting.

  • Alert Notifications — Send automated alert emails when a monitored metric crosses a threshold, CC-ing a human operator for oversight.

  • Report Delivery — Generate and send periodic summary reports to stakeholders with BCC to an archive inbox for record-keeping.


Agent Mail Update Message

What it is

Add or remove labels on an email message. Use for read/unread tracking, campaign tagging, or state management.

How it works

The block calls the AgentMail API to modify the labels on a specific message. You can add new labels, remove existing ones, or do both in a single call. Labels are arbitrary strings you define, making them flexible for tracking message state such as read/unread, processing status, or campaign membership.

The block returns the updated message ID and the complete message object reflecting the current label state. This is useful as a downstream step after processing a message, allowing you to mark it as handled so it is not picked up again by a polling workflow.

Inputs

Input
Description
Type
Required

inbox_id

Inbox ID or email address the message belongs to

str

Yes

message_id

Message ID to update labels on

str

Yes

add_labels

Labels to add (e.g. ['read', 'processed', 'high-priority'])

List[str]

No

remove_labels

Labels to remove (e.g. ['unread', 'pending'])

List[str]

No

Outputs

Output
Description
Type

error

Error message if the operation failed

str

message_id

The updated message ID

str

result

Complete updated message object with current labels

Dict[str, Any]

Possible use case

  • Read/Unread Tracking — Remove the "unread" label and add "read" after an agent processes a message, preventing duplicate processing on the next polling cycle.

  • Pipeline State Management — Add labels like "sentiment-analyzed" or "response-drafted" as a message moves through multi-step processing, so each stage knows which messages still need work.

  • Priority Tagging — Add a "high-priority" label to messages from VIP senders or containing urgent keywords, enabling downstream blocks to filter and handle them first.


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