SMTP authentication provides a powerful tool for controlling relaying with a maximum of flexibility. And other new antispam features in 8.10 increase the granularity, power, and ease of use of sendmail's spam-fighting toolkit. The information here will help you put those tools to work. For further information, refer to those sources, or direct questions to comp.mail.sendmail , the Usenet newsgroup for open source sendmail. This feature provides a high degree of flexibility without resorting to multiple maps.
Most people find they can live with that tradeoff.
These arguments thus allow for simple exceptions from the normal tests. The header checks made possible in sendmail 8.9 have been enhanced in sendmail 8.10. Adding headers Headers can be added to a message, notably in combination with the new macro map. The htemplate is macro-expanded before insertion into the message. If one of these headers is in the input, it will be reflected to the output regardless of these flags or macros.