Using the forum posts, I have implemented sending dunning letters per email.
I want that if the debitor email address is empty then the dunning letter is printed by paper.
I tried modifiyng user exit EXIT_SAPF150D_001 so that if the email address is empty, the output device is set to '1', that is printer: FINAA-NACHA = '1'
So I create a dunning run (F150) as usual, selects the ouput device 'EMAIL' (created for email output)
For customers without email address, there is a spool request created but it does not come out of the printer, it still contains the original output device 'EMAIL'. I don't know if I need more coding in the user exit or...
Thank you for your help.