Fetch Email Attachment

Retrieves the content of an email attachment from Outlook/Microsoft 365. This action downloads the raw attachment data for processing or storage.

Overview

Purpose: Download email attachment content from Outlook messages.
Use Cases: Downloading invoice PDFs, extracting document attachments, processing image files, archiving attachments, automated document workflows, compliance and record-keeping.
API Method: GET /fetch-attachment
Microsoft Graph API: Uses Microsoft Graph /v1.0/me/messages/\{messageId\}/attachments/\{attachmentId\}/$value endpoint.
Required Scope: Mail.Read

Thread ID: The unique identifier of the email message (message ID in Microsoft Graph terminology).

Attachment ID: The unique identifier of the specific attachment within the message.

Email Sync: Use the ‘emails’ sync to retrieve email messages with attachment metadata.
Attachment Metadata: Each email’s attachments array contains attachment IDs, filenames, MIME types, and sizes.
Message ID: The thread ID parameter refers to the message ID from Microsoft Graph (not the conversation ID).
Workflow: First sync emails, then use attachment IDs from the sync data to fetch specific attachments.

Raw Content: Returns the attachment content as a string (binary data).
Format: The data format depends on the attachment type (binary for files, text for documents).
Processing: You may need to handle encoding/decoding based on the attachment’s MIME type.

Binary Files: For PDFs, images, and other binary files, handle as binary data.
Text Files: For text-based attachments, the content is returned as text.
MIME Type: Use the MIME type from attachment metadata to determine file type and processing method.
Filename: Use the filename from attachment metadata for saving the file.
Size Limits: Be aware of attachment size limits when processing large files.

[!IMPORTANT] OAuth Scope: Requires Mail.Read scope for reading emails and attachments.

Read-Only: This scope allows reading emails and attachments but not sending or modifying.
User Consent: Users must grant permission to read their emails during OAuth flow.

Invalid IDs: Returns an error if the message ID or attachment ID doesn’t exist.
Permissions: Fails if the user hasn’t granted the required Mail.Read scope.
Retry Logic: Automatically retries failed requests up to 3 times.
Large Files: Very large attachments may timeout - consider implementing timeout handling.

Invoice Processing: Download invoice PDFs from emails for automated processing and accounting.
Document Archival: Save important document attachments to cloud storage or document management systems.
Image Extraction: Extract images from emails for display, processing, or analysis.
Data Import: Download CSV or Excel files from emails for data import workflows.
Compliance: Archive email attachments for regulatory compliance and record-keeping.
Automated Workflows: Trigger actions based on attachment content (e.g., OCR, data extraction).

[!TIP] First sync emails to get attachment IDs - you can’t fetch attachments without them

[!IMPORTANT] The ‘threadId’ parameter is actually the message ID from Microsoft Graph

[!TIP] Use attachment metadata (filename, MIME type, size) from the email sync for proper file handling

[!WARNING] Check attachment size before fetching to avoid memory issues with large files

[!TIP] Implement error handling for missing or deleted attachments

[!TIP] Store attachment IDs if you need to fetch the same attachment multiple times

[!TIP] Consider caching downloaded attachments to reduce API calls

[!TIP] Use the MIME type to validate file types before processing

[!TIP] For large attachments, implement streaming or chunked processing if possible

[!IMPORTANT] Ensure your OAuth flow requests the Mail.Read scope

[!TIP] Test with various file types (PDF, images, documents) to ensure proper handling

[!TIP] Handle encoding appropriately based on the attachment’s content type

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