''from='' '''

The from= syslog equate shows the envelope sender:

from=addr

The addr is the address of the envelope sender with any RFC2822 commentary (Section 25.3.4) removed. This will usually be the address of an actual person, but it can also be postmaster or the value of the $n sendmail macro in the case of a bounced message. The from= syslog equate is shown only for sender records.