Fax Extensions / ext-fax in FreePBX 2.7

I tried to configure a test setup with a Test Fax-to-Email user (e.g. with User extension 10021, Fax enabled and Fax Email configured). The dialplan ist created in [ext-fax], but when trying to call 10021 from internal, it never gets there. No wonder, ext-fax is not called at all… What else do I have to do in order to get Fax working?
Include ext-fax in from-internal context?
Or add faxdetect on from-internal context as per http://www.freepbx.org/forum/freepbx/users/add-faxdetect-on-from-internal-context ?
Anyhow, I don’t find it really logical that the fax extension is not included by some sorts by default…

Some notes on my environment:

  • Asterisk 1.4.30 (with some patches, e.g. for faxing)

  • Fax apps:
    ( output of asterisk -rx “show applications” | grep -i “fax”)
    NVBackgroundDetect: Background a file with talk and fax detect (IAX and SIP too)
    NVFaxDetect: Detects fax sounds on all channel types (IAX and SIP too)
    ReceiveFAX: Receive a FAX
    RxFAX: Receive a FAX
    SendFAX: Send a FAX
    TxFAX: Send a FAX

  • FreePBX in DeviceAndUserMode