EXIM debugging option "debug_print" unknown
You are getting the error because debug_print is not a valid option for an authenticator, which appears to be what you are configuring. debug_print is a transport option.
Tips for debugging exim
- Test your configuration without restarting exim:
exim -bV - Test how exim will route a given address:
exim -bh 192.168.254.170 - Trace a pretend SMTP transaction:
exim -bt [email protected]
Ref: Exim Cheatsheet