# Publish an SPF record indicating that only shenron sends mail
-'openstreetmap-uk:v=spf1 include\072openstreetmap.org ~all
+'openstreetmap-uk:v=spf1 include\072openstreetmap.org -all
+
+# Delegate MTA-STS policy
+
+C_mta-sts.openstreetmap-uk:_mta-sts.openstreetmap.org
# Main web servers and their aliases