No. As Matthias pointed out, these are the settings before the content filter (hint: it is before spamassassin). Unfortunately, your configuration uses the /usr/sbin/sendmail command to inject filtered mail back into Postfix. That uses the same Postfix pickup service for new mail and for filtered mail. Therefore if you turn off virtual alias expansion afer the content filter, then you turn off virtual alias expansion for all mail received with the /usr/sbin/sendmail command. Instead I recommend that you use an approach that uses SMTP to reinject mail back into Postfix. Thgis gives finer control over the receive_override_options setting. See, for example, http://www.postfix.org/FILTER_README.html.
OK, thanks for the additional guidance. The root cause of my problems is trying to get this set up with random config samples found on the internet and having only a vague understanding of the big picture. Although that approach got me something functional and working, I obviously have a lot more reading to do.
