How to send a Fax using your email To send a fax, compose a new email. In the to address, enter the 10 digit fax number with @fax.level365.com. For example, a fax number of (555) 123-4567 would be 5551234567@fax.level365.com. The subject and body of the email will act as the cover sheet. Attach the document you wish to fax to the email and click Send. For best results, we recommend sending (1) attachment per eFax. Documents cannot be password protected/encrypted. Supported file types include, but are not limited to: .PDF .DOC .DOCX .RTF .TIF .TIFF .TXT