sendmail, 4th Edition

Dangerous Write Permissions

The sendmail program, of necessity, needs to trust its configuration file. To aid in the detection of risks, it checks the permissions of its configuration file when first reading that file. If the file is writable by group or world, sendmail logs the following message:^[72]

configfile: WARNING: dangerous write permissions

If sendmail is being started as a daemon or is being used to initialize the aliases database, it will print the same message to its standard error output.

^{[72] *} This is done only when not in rule-testing mode to prevent spurious warnings when you already know you are using a weak configuration file with -C.