Very difficult to answer without any details.
Anyway, attaching e-documents to emails is seldom a good idea; attachments can get lost, corrupted, misdirected, and there is always the size limit.
Far better using a file sharing service like https://cloud.acrobat.com/ (there are countless others like Dropbox, Google Drive, Microsoft OneDrive, ...), upload the doc, then insert the shared download link into the email message.