Emails and attachments have size limits for both sending outbound messages through Postmark or receiving messages as JSON with inbound processing. This help article will make you aware of what size limits are in place for both outbound sending and inbound processing, which will be useful for troubleshooting sending or inbound processing errors and advising your application’s users of best practices.
Sending Size Limits
- TextBody and HtmlBody can each be up to 5 MB each
- Total message size, including attachments, can be 10 MB
Inbound Size Limits
- Total cumulative size for all Inbound attachment files may not exceed 25 MB