The F configuration command (Section 22.1.2) allows the specification of a scanf(3)-style string to aid in parsing files (Section 22.1.2.1). This ability is enabled at compile time by default. If you don't need it, you can exclude its support with the following line in your Build m4 file:

APPENDDEF(`confENVDEF', `-DSCANF=0 ')
                                 
               disable scanf(3)

The scanf(3) function is used only in reading files into a class with the F configuration command.

If you are running a precompiled sendmail binary, you can use the -d0.1 debugging command-line switch (-d0.1) to determine if SCANF support is included (if it appears in the list, support is included).