[exim] blocking apostrophe emails

Hello,

Does it make sense and does any one have a rule to block emails based on
whether in the FROM field there are characters like ' (e.g.
Kirstenspider's@???)?

I get quite a few such spam emails and not all are caught by RBLs. From
what I understand apostrophes are not allowed in email addresses? Thanks
for advice.

Warm regards,

--
Zbigniew Szalbot