# Email Attachments

Customer.io doesn’t support attachments of any type in [Campaigns or Broadcasts](/journeys/types-of-campaigns-and-broadcasts/). But, there are other, better ways to send files to recipients!

 Try sending a transactional message

Rather than trying to send links, or add attachments to events, you can send attachments as a part of our [transactional message service](/journeys/email-attachments/#file-attachments-with-the-transactional-api).

## Why you shouldn’t send attachments[](#why-you-shouldnt-send-attachments)

Sending attachments can create problems for your deliverability. Here’s a non-exhaustive list of potential problems stemming from attachments:

*   Email attachments are often used to hide viruses and malware, so they are more likely to end up in spam folders or flagged as potentially malicious.
*   Some email servers have strict policies around message size limits and/or attachments which can cause messages to bounce.
*   Attachments impose a larger download for recipients, which can impact their data consumption and/or lead them to ignore your email.

All of these can damage your [deliverability](/journeys/email-deliverability-best-practices/).

## Send a link rather than an attachment[](#try-sending-a-link-rather-than-an-attachment)

 Include PDF attachments from the asset library

While you can encode attachment and send them directly to people, you can also host PDFs in our [asset library](/journeys/asset-library) and link to them in your messages. This can save you the trouble of encoding and sending files directly.

If you want to send a file to your recipients, the best approach is to send them a link to a landing page where they can download the file.

1.  You should host the file online—either on your own server or a cloud storage service like AWS S3, Google Drive, Dropbox, Box, etc.
2.  Create a page that links to the file. Your hosting service might already create one for you. Otherwise, you’ll need to add a page to your website.
3.  Copy that page’s URL and use it in your email.

 Avoid sending a link to a file directly

You can send a link to the file itself, but be aware that some spam filters and algorithms have been known to follow links to evaluate them, and if the link leads to a file, it could be considered suspicious. Microsoft Office files are particularly risky.

While more convoluted than using a direct link, this approach helps ensure that your emails are not flagged as spam.

## Send attachments with transactional messages[](#file-attachments-with-the-transactional-api)

In cases where an attachment is unavoidable, you can send them using our [Transactional API](/journeys/transactional-api/#list-of-supported-parameters) through an `attachments` parameter.

With this parameter, you can specify a dictionary of attachments where the filename is the key and the value is the base64-encoded content. **The total size of all attachments must be less than 2 MB.** Do note that some filetype extensions are restricted.