[EXIM] bad address

I use this smarthost entry with 1.80:

punt:
driver = smartuser,
no_verify;
new_address = ${local_part}@???,

I got the following problem, what can be done (if anything):

1997-12-09 21:36:50 "Arlie Scheppke"@???: punt director deferred: <arlie scheppke@???> - bad address generated by punt director: missing or malformed local part (expected word or "<")\n
*** Frozen ***

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