Sendmail, 3rd Edition

The qf File Internals

The qf file holds all the information that is needed to perform delivery of a queued mail message. The information contained in that file, and its appearance, changes from release to release of sendmail. Here, we document the qf file that is used with V8.12 sendmail. Note that V8.7 introduced a V version line that enabled later versions to correctly process older versions’ queue files.

This section must be taken with a proverbial grain of salt. The internals of the qf file are essentially an internal interface to sendmail and, as such, are subject to change without notice. The information offered here is intended only to help debug sendmail problems. It is not intended (and we strongly discourage its use) as a guide for writing files directly to the queue.

The qf file is line-oriented, containing one item of information per line. Each line begins with a single character (the code character), which specifies the contents of the line. Each code character is followed, with no intervening space, by the information appropriate to the character. The complete list of code characters is shown in Table 11-6.

Table 11-6. qf file code characters

Code	§	Meaning	Version	How many
A	A line	AUTH= parameter	V8.10 and above	At most, one
B	B line	Message body type	V8.6 and above	At most, one
C	C line	Set controlling user	V5.62 and above	At most, one per R line
d	d line	Data file directory	V8.12 and above	Exactly one
D	D line	Data filename	Obsolete ...