You can send attachments up to 10 MB from Seller Central for specific contact reasons. If you use your own email service (for example, Outlook), the 10 MB limit applies to both email text and any attachments combined.
You can send one or more attachments (up to 10 MB) in your replies to a buyer’s message. Buyers similarly can send one or more attachments (up to 10 MB).
The following formats are supported: