Might incorporating this work?
select case when isnumeric(left(DCPI_Date,4))=1
then DCPI_Date
else '19000101'
END
when doing your insert into dbo.Reliance_Master
Then later in your SSIS redirect those rows that have 1900-01-01 as the date to an separate file for visual inspection or other form of importing, for instance.
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