Using attachments in Buttondown

Buttondown allows you to add file attachments to your emails, making it easy to share documents, images, and other files with your subscribers. Whether you're sending a PDF report, sharing a calendar invite, or distributing a resource, attachments make your emails more versatile.

Buttondown supports the following file types for attachments:

Each attachment is limited to a maximum size of 2 MB. This limit helps ensure reliable delivery across email providers. If you need to share larger files with your subscribers, consider uploading them to a file sharing service (like Dropbox, Google Drive, or AWS S3) and including a link in your email instead.

• While composing or editing an email in Fancy mode, type "/attachments" then select the file
• In Markdown mode, drag and drop the file from your computer to the Editor

If you're using Buttondown's API to create or update emails, you can include attachments by:

1. First uploading the attachment using the /v1/attachments endpoint
2. Then referencing the attachment ID in your email creation/update request

Here's an example of adding an attachment via the API:

// First, upload the attachment
// You need to create FormData with the file and a name
const formData = new FormData();
formData.append('file', yourFileObject);
formData.append('name', 'Your File Name.pdf');

const attachmentResponse = await fetch('https://api.buttondown.com/v1/attachments', {
  method: 'POST',
  headers: {
    'Authorization': `Token ${YOUR_API_KEY}`
    // Note: Don't set Content-Type header with FormData, 
    // the browser will set it correctly with the boundary
  },
  body: formData
});

const attachment = await attachmentResponse.json();

// Then, create or update an email with the attachment
const emailResponse = await fetch('https://api.buttondown.com/v1/emails', {
  method: 'POST',
  headers: {
    'Authorization': `Token ${YOUR_API_KEY}`,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    subject: 'Email with attachment',
    body: 'Check out the attached file!',
    attachments: [attachment.id] // Include attachment IDs as an array
  })
});

You can also update an existing email to add attachments:

// Adding an attachment to an existing email
const updateResponse = await fetch(`https://api.buttondown.com/v1/emails/${emailId}`, {
  method: 'PUT',
  headers: {
    'Authorization': `Token ${YOUR_API_KEY}`,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    attachments: [attachment.id]
  })
});

When you send an email with attachments:

1. Buttondown automatically includes the attachments in the outgoing emails
2. Recipients will see the attachments displayed according to their email client's conventions
3. For web archive views, attachments will be available for download

Adding attachments to emails is a premium feature in Buttondown. If you have a free account, you'll need to upgrade to a paid plan to use this functionality. You can check the current pricing and upgrade options on the Buttondown pricing page.

Attachments can be tricky to get right without getting your email filtered as spam. Here are some best practices:

• Keep sizes small: Even though the limit is 2 MB, smaller attachments (under 1 MB) will deliver more reliably
• Use descriptive filenames: Help your subscribers understand what the file contains
• Consider accessibility: For documents, ensure they're accessible to readers with disabilities when possible
• Limit the number of attachments: Too many attachments can trigger spam filters or make emails difficult to receive
• Test before sending: Send a test email to yourself to ensure attachments appear correctly
• Check delivery rates: Monitor your email analytics after sending to ensure deliverability remains high
• Compress files when possible: Use ZIP compression for multiple files or to reduce overall size

If you need assistance with attachments, contact Buttondown support for help.