Already fixed early 2010. You need to upgrade to Postfix 2.8 or
later. I don't know if this will be back-ported to earlier releases.
Wietse
20100422
Workaround (introduced: postfix-19990906 a.k.a. Postfix
0.8.0). The Postfix local delivery agent did not properly
distinguish between "address has no extension" and "address
has an extension, but the extension is invalid". In both
cases it would run only the full recipient local-part through
the alias maps. Instead, it now drops the faulty extension
from the recipient address local-part (it would be too
error-prone to replace all tests for "no extension" by tests
for "no valid extension". File: local/recipient.c.
