MailTips during migration

During the coexistence period of a migration, MailTips will warn users that "Some members of <distribution list> are outside of your organization" when sending to a distribution list that has some users in the source exchange org and others in the target org.  In past migrations that I've done, mailtips have been completely disabled to avoid this behavior since it can be misleading to end-users.  This is, however, a useful feature to end users.  Is there a way to "Trust" the source/target exchange organizations so that this will work the way that an end user would expect it to?