Apache returns the following error in the error_log:

/usr/local/apache/bin/httpd: error in loading shared libraries: /usr/local/apache/libexec/php3_vmailmgr
.so: undefined symbol: _vm_adduser

My php3.ini file has the following entries:

extension_dir   =       /usr/local/apache/libexec
extension = php3_vmailmgr.so

The code that causes the error is:

$vdomain = "tld.org";
$vpassword = "somepassword";
vm_adduser($vdomain,$vpassword,"username","foobar");