For certain types of files uploaded to Amazon S3, you may need to request that Amazon serve the file a certain way by using custom headers.

To set custom headers for S3 files:

1. Choose Transmit > Settings…
2. Click Cloud
3. To add default headers for all S3 uploads, click Default, otherwise click to add your own file type extensions, such as “mp3”, “zip”, etc.
4. Click to add a header for the selected extension, or click and hold to choose from a list of commonly used headers.
5. Type in the value you wish to set for that header.
6. Use the checkbox next to the header to enable or disable that particular header.

To remove a rule or extension, select it in the list and click