Via:
An unofficial trace header Obsolete
The Via:
header is
not defined by RFC2822 but occasionally appears in
mail messages that sendmail
needs to process. It is used by a few other networks
to mark a mail message’s transit through a
forwarding host. It is an early, and now obsolete,
version of the Received:
header. The
sendmail program counts the
Via:
header
when determining the hop count but has no other use
for it.
The Via:
header
should never be declared in the configuration
file.
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.