Does the email text go through but not the attachment or is the email actually blank and no attachment?
How large is the file being attached? It may just be too big.
What email app are you using and what service - Gmail or...?
If it's too big a file to email, you could upload it to the cloud, like Google Drive or Dropbox, and email a link to it.
Android since v1.0. Linux user since 2001.