[Exim] 501 malformed address

Does this look like something that would be generated by Exim? If so,
would it be in the logs? (I can't find it if there is a log entry):

501 <5102715492@???> RET=HDRS ENVID=16792718l:
malformed address: RET=HDRS ENVID=16792718l may not
follow <5102715492@???>

TIA,

--
Troy Settle
Pulaski Networks
http://www.psknet.com
540.994.4254 - 866.477.5638