PO output - pdf - output not trigerring

Hi Experts,

I am configuring mail output(adobe pdf form) in SRM standalone system.

1. Define Actions for Document Output:

Action profile - BBP_PD_PO

- Time processing: Processing when saving document

- processing type: custom PDF form

- form type: pdf-based forms

- format: BBP_PO_ADB_MAIL

2. Condition dependent output

- schedule condition: default output is mail

other settings are picked from action profile.

- Is start condition necessary, I left blank ?

3. SCOT - mail node in use

4. Output medium is mail for vendor

what else is missing ? still output is not triggering but I can see print preview. I don't see anything in SOST as well.

your help is highly appreciated.