sendmail, 4th Edition

Ordinarily, makemap is safety-conscious. It will issue a warning, or abort, if any of the following three circumstances are present.

If makemap is run by root , and if the directory into which the database will be written is writable by anyone other than root , makemap will issue this warning:

WARNING: World writable directory directory

If the database file already exists and is a symbolic link, makemap will print the following error and abort:

makemap: error creating type hash map access: Symbolic links not allowed

Finally, if the database file already exists and is a hard link, makemap will print this error and abort:

makemap: error creating type hash map access: Hard links not allowed

If you wish to override these causes for rejection , you can do so by using this -s switch. But be aware that these warnings and errors are printed for good reasons. Circumventing them might open your machine to security risks.