If you use AWS S3 to store data you can send attachments as https: or http: URLs. You can also send attachments as s3 protocol URIs which look like s3://bucket/key.

To access private s3 objects, We use Cross-account Access.

Cross-account Access

We will fetch attachments from your S3 bucket, using AWS account ID 475757276268 (canonical ID d4b5723a54db6f9da8a68f4c24233880793bf1d68dd11e7e2b4989bd2c71c59a). You will need to grant access to Playment using bucket policies or on set permissions on objects using ACLs.

We suggest setting a Bucket Policy that shares the bucket's contents with Playment's account.

Here's a sample bucket policy:

"Version": "2012-10-17",
"Statement": [
"Sid": "playment-s3-access",
"Action": [
"Effect": "Allow",
"Principal": {
"AWS": [
"Resource": "arn:aws:s3:::YOUR_BUCKET_NAME/*"

Replace YOUR_BUCKET_NAME with the name of your bucket, leaving the /* as shown or replacing it with a more specific bucket path to further restrict access.

If you are using ACLs (Access Control Lists), you need to update the ACL individually for each object to grant read access to our account, as Bucket ACLs can't grant read permissions to nested objects.