NEW FEATURE - TrustFax has added an allowed sender list. You can now send an email to fax without using the security identiifers if your email is listed in the allowed sender list in your trustfax account. You can setup the allowed sender list in your account info - preferences section of your Trustfax.
Using the security identifiers will allow you to send an email to fax from any email address. The allowed sender list makes it possible to send from certain email addresses without additional identifiers.
Using the allowed sender list is similiar as the security identifier method but you send the email to fax_number[at]send.trustfax.com. the fax_number would be the actual fax number of intended receiptient's fax machine.
You can still use the coverpage:no statement if you do not want a trustfax generated coverpage. The sujbect field and the attention: and message: statment can still be used in the body of the email when you want a coverpage to be sent with the fax attachment.
A link to the send fax help page: http://www.trustfax.com/guides/tf/tf_send.html#send_email