Please file a bug report with your distribution.
Postfix 2.10 as distributed by me will add a backwards-compatibility
setting to main.cf, thusly:
# postfix upgrade-configuration
COMPATIBILITY: editing /etc/postfix/main.cf, overriding
smtpd_relay_restrictions to prevent inbound mail from unexpectedly
bouncing. Specify an empty smtpd_relay_restrictions value to
keep using smtpd_recipient_restrictions as before.
And the backwards compatible setting is:
# postconf smtpd_relay_restrictions
smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated
defer_unauth_destination
If your distributor has removed this backwards-compatibility safety
net, then please tell them that they are doing their users a disservice.
Wietse
