Sendmail, 3rd Edition

Name

X-Authentication-Warning:

Synopsis

If the PrivacyOptions option (PrivacyOptions) is declared with authwarnings, V8 sendmail inserts a special header line for possible security concerns. That header line looks like this:

X-Authentication-Warning: host: message

Here, host is the canonical name of the host that inserted this header. The message is one of the following:

Processed by user with -C file

An attempt was made by a user other than root to run sendmail with the -C command-line switch. That switch caused sendmail to read file in place of the system sendmail.cf file.

user set sender to other using -f

A user or program’s user identity used the -f command-line switch to change the identity of the sender to other (and user was not listed with the T configuration command). This can be legitimate when the user is uucp or daemon. It can also be legitimate when the user is sending to some mailing lists (Section 10.8). Such a warning can also indicate that someone is trying to forge mail.

user owned process doing -bs

A user or program’s user identity used the -bs command-line switch to make sendmail receive a mail message via its standard input/output using the SMTP protocol (and user was not listed with the T configuration command). This parallels network notification set up by defining IDENTPROTO when compiling sendmail and by use of the $_ macro ($_) in Received: headers.

Processed from queue dir

A user other than root used the -oQ (or similar) switch (QueueDirectory) to process mail ...