[exim] regex confusion

I know this is a simple question, but there is something fundamental
that I am just not getting by reading the docs regarding regex in
exim. I put the following in my data ACL:

acl_check_content:

accept regex = (To|Cc):.*nospam-.*(\n|\r)

which is intended to match addresses with a nospam- prefix in To or
Cc lines, to bypass spam filtering and absolutely get a message
accepted. The above string seems to match everything, however, and
effectively disables my filtering.

If I put the same basic string in pcretest, minus the (\n|\r), it
seems to work fine. But removing the (\n|\r) from the string in my
exim config file makes no difference.

What basic fact of using regex am I missing here?

Thanks!

--
Mark Edwards
mark@???
cell: +46704070332