Uploads
Each department can be configured to allow attachments:
Enable uploading files for: Everyone/Registered users/Nobody
Allowed extensions: each extension on a new line. Please note that allowing extensions such as php to be uploaded you compromise your server security
Maximum upload size (MB): This is the maximum size of the upload, in megabytes (1 MB = 1024 kb). To disable this, just set it to 0.
Maximum files allowed: Users can submit multiple files by clicking on the Add another attachment button. If you want to limit this, set a value greater than 0. Note that the upload size and maximum uploaded files can also be restricted by your hosting provider.