This should get you going...
To benefit from the 20ValidateLocalRecipients you should create your users/pseudonyms under SME. To bypass you need to do the following:
# mkdir -p /etc/e-smith/templates-custom/var/qmail/control/mailrules.default
# cd /etc/e-smith/templates-custom/var/qmail/control/mailrules.default
# touch 20ValidateLocalRecipients
# /sbin/e-smith/signal-event email-update