In your Gmail account connected to Popfax.com click on the "compose" button to create a new message.
In address line, type email@example.com.
In the subject line, type the security code from your Popfax account.
In the "Mail to fax" section of your account copy the current security code. Or you can, alternatively, choose your own security code.
In the message body type the fax numbers.
Attach the document to be sent by fax in ∗pdf, ∗doc, ∗jpg, ∗png, etc. and send the message.
In a short time, you will receive the fax transmission report. All transmission reports are also stored in the Cloud and can be accessed from your Popfax.com online account.
For more tutorials see following links:
Try to fax from Gmail now!