Distribution lists in your mail
Send a fax message to a group, just like you send an email to a group. Just add the eFax-addresses (mobilenumber@efax.nu) in the email message "To"-field.
You can also save your eFax-recipients as contacts, and then create your own distribution lists in your email client.
If you want to send a fax to more than a couple of hundred recipients, TellusTalk recommends the Broadcast facility.