--- spec.texinfo-orig	Wed Jun 20 14:22:14 2001
+++ spec.texinfo	Wed Jun 20 14:17:47 2001
@@ -7272,6 +7272,7 @@
 * message_filter_pipe_transport::
 * message_filter_reply_transport::
 * message_filter_user::
+* message_id_header_domain::
 * message_id_header_text::
 * message_size_limit::
 * message_size_limit_count_recipients::
@@ -9097,7 +9098,7 @@
 
 
 @cindex uid: system filter
-@node message_filter_user, message_id_header_text, message_filter_reply_transport, Main configuration
+@node message_filter_user, message_id_header_domain, message_filter_reply_transport, Main configuration
 @findex message_filter_user
 @unnumberedsubsec message_filter_user @emph{option}
 
@@ -9113,7 +9114,20 @@
 If the option is not set, the uid is not changed from the Exim user (or root if
 there is no Exim user) when running the system filter.
 
-@node message_id_header_text, message_size_limit, message_filter_user, Main configuration
+@node message_id_header_domain, message_id_header_text, message_filter_user, Main configuration
+@findex message_id_header_domain
+@unnumberedsubsec message_id_header_domain @emph{option}
+
+Type: string, expanded@*
+Default: unset
+
+If this variable is set, the string is expanded and used as right hand side
+(domain-part) in the @dfn{Message-id:} header that Exim will create if an incoming
+message does not have one. If this is unset the primary hostname will be used. Only
+the characters A-Z, a-z, 0-9, . and - are accepted, all others are replaced by
+hyphens.
+
+@node message_id_header_text, message_size_limit, message_id_header_domain, Main configuration
 @findex message_id_header_text
 @unnumberedsubsec message_id_header_text @emph{option}
 
@@ -23592,7 +23606,9 @@
 If an incoming message does not contain a @dfn{Message-id:} header, Exim constructs
 one and adds it to the message. The id is constructed from Exim's internal
 message id, preceded by the letter E to ensure it starts with a letter, and
-followed by @@ and the primary host name. Additional information can be
+followed by @@ and the primary host name or the value of
+@cindex message_id_header_domain
+@dfn{message_id_header_domain} option. Additional information can be
 included in this header by setting the
 @cindex message_id_header_text
 @dfn{message_id_header_text} option.