CARET Legal and most email providers limit their email attachment sizes to 20mb. This limit is for Documents and Invoices attached from CARET Legal, as well as Attachments uploaded from the local computer.
Most of the time attorneys are sending PDF files and sometimes those PDFs are larger than 20mb. You would be able to reduce/shrink the file size without any noticeable changes. Please refer to your PDF softwares (Adobe, Nitro) for instructions.