Get full access to sendmail, 4th Edition and 60K+ other titles, with a free 10-day trial of O'Reilly.

There are also live events, courses curated by job role, and more.

Chapter 25, The H (Headers) Configuration Command

No balancing with $>+ on page 1133	Header fields are now 8-bit clean (8.14)
No balancing with $>+ on page 1133	Preserve spaces after the colon in a header (V8.14)
No balancing with $>+ on page 1133	Special characters no longer need to balance with `$>+` (8.13)
H_RECEIPTTO Header Flag (V8.7 and Later) on page 1141	The `Delivery-Receipt-To:` header is treated the same as a `Return-Receipt-To:` header (8.13)
Message-ID: on page 1159	The `confMESSAGEID_HEADER` mc macro allows the `Message-Id:` header’s value to be defined (8.13)
${msg_id} on page 834	The new `${msg_id}` macro holds `Message-Id:` header’s value (8.13)

Get sendmail, 4th Edition now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.

Start your free trial

Don’t leave empty-handed

Get Mark Richards’s Software Architecture Patterns ebook to better understand how to design components—and how they should interact.

It’s yours, free.

Get it now

Check it out now on O’Reilly

Dive in for free with a 10-day trial of the O’Reilly learning platform—then explore all the other resources our members count on to build skills and solve problems every day.

Start your free trial Become a member now