Sun Java System Messaging Server 6.3 Administration Guide

11.5.6 Syntax Checks After Rewrite

No additional syntax checking is done after the rewrite rules have been applied to an address. This is deliberate—it makes it possible for rewrite rules to be used to convert addresses into formats that do not conform to RFC 822. However, this also means that mistakes in the configuration file may result in messages leaving the MTA with incorrect or illegal addresses.