When checking files and directories for group read and write permissions, sendmail checks the group of the controlling user. On systems that allow a user to belong to one group at a time, failure stops here with the check for that one group. On systems that allow users to belong to many groups at once, failure causes sendmail to check the other groups to which the controlling user might belong. It finds the list of groups by calling getgrgid(3).

If your system lacks the getgrgid(3) call or doesn't need it, you should exclude this code by defining NO_GROUP_SET in sendmail/conf.h. NO_GROUP_SET causes the code containing the call to getgrgid(3) to be excluded from sendmail. Be aware that excluding getgrgid(3) support on systems that need it can cause delivery to files to fail in mysterious ways.

If you are running a precompiled version of sendmail, be aware that there is no debugging switch that can tell you what the setting of NO_GROUP_SET was set to at compile time.

Note that NO_GROUP_SET affects only inclusion of the getgrgid(3) system call. See the DontInitGroups option (DontInitGroups) for a means to exclude the getgrgid(3) and initgroups(3) system calls by means of your configuration file.

New ports should be reported to sendmail@sendmail.org so that they can be folded into future releases.