installation location. Additionally, note the following prominent message that you helpfully reproduced:

So it's seems that courier have problems with determine userid. The user is not obliged to use ONLY root or mail user. I can put condor (uid=1000(condor) gid=100(users) groups=100(users)) instead of vpopmail and result is the same, so this is the problem of configure script. I have full functional worked vpopmail. As you see i disabled all auth methods without authvchkpw because i want to use only this method. I current use courier-mta 0.59.3 version compiled successful with the same parameters and worked fine. If the problem is in my something in my vpopmail this line in this case will not to be in config.log file: vpopmail_home='/var/vpopmail' with others successful test of vpopmail support.

Here is confirmation is not in configure:

./configure --without-authuserdb --without-authpam --without-authldap --without-authpwd --without-authshadow --without-authpgsql --without-authmysql --without-authcustom --with-mailuser=condor --with-mailgroup=users checking for a BSD-compatible install... /usr/bin/ginstall -c checking whether build environment is sane... yes checking for a thread-safe mkdir -p... /usr/bin/mkdir -p checking for gawk... gawk checking whether make sets $(MAKE)... yes checking for gawk... (cached) gawk checking for gcc... gcc checking for C compiler default output file name... a.out checking whether the C compiler works... yes checking whether we are cross compiling... no checking for suffix of executables... checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether gcc accepts -g... yes checking for gcc option to accept ISO C89... none needed checking for style of include used by make... GNU checking dependency style of gcc... gcc3 checking how to run the C preprocessor... gcc -E checking for a BSD-compatible install... /usr/bin/ginstall -c checking whether ln -s works... yes checking for perl5... no checking for perl... /usr/bin/perl checking for sysconftool...... ././sysconftool checking for lt_dlinit in -lltdl... yes checking build system type... i686-pc-linux-gnu checking host system type... i686-pc-linux-gnu checking for a sed that does not truncate output... /usr/bin/sed checking for grep that handles long lines and -e... /usr/bin/grep checking for egrep... /usr/bin/grep -E checking for ld used by gcc... /usr/i486-slackware-linux/bin/ld checking if the linker (/usr/i486-slackware-linux/bin/ld) is GNU ld... yes checking for /usr/i486-slackware-linux/bin/ld option to reload object files... -r checking for BSD-compatible nm... /usr/bin/nm -B checking how to recognise dependent libraries... pass_all checking for ANSI C header files... yes checking for sys/types.h... yes checking for sys/stat.h... yes checking for stdlib.h... yes checking for string.h... yes checking for memory.h... yes checking for strings.h... yes checking for inttypes.h... yes checking for stdint.h... yes checking for unistd.h... yes checking dlfcn.h usability... yes checking dlfcn.h presence... yes checking for dlfcn.h... yes checking for g++... g++ checking whether we are using the GNU C++ compiler... yes checking whether g++ accepts -g... yes checking dependency style of g++... gcc3 checking how to run the C++ preprocessor... g++ -E checking for g77... g77 checking whether we are using the GNU Fortran 77 compiler... no checking whether g77 accepts -g... yes checking the maximum length of command line arguments... 32768 checking command to parse /usr/bin/nm -B output from gcc object... ok checking for objdir... .libs checking for ar... ar checking for ranlib... ranlib checking for strip... strip checking if gcc supports -fno-rtti -fno-exceptions... no checking for gcc option to produce PIC... -fPIC checking if gcc PIC flag -fPIC works... yes checking if gcc static flag -static works... yes checking if gcc supports -c -o file.o... yes checking whether the gcc linker (/usr/i486-slackware-linux/bin/ld) supports shared libraries... yes checking whether -lc should be explicitly linked in... no checking dynamic linker characteristics... GNU/Linux ld.so checking how to hardcode library paths into programs... immediate checking whether stripping libraries is possible... yes checking for shl_load... no checking for shl_load in -ldld... no checking for dlopen... no checking for dlopen in -ldl... yes checking whether a program can dlopen itself... yes checking whether a statically linked program can dlopen itself... no checking if libtool supports shared libraries... yes checking whether to build shared libraries... yes checking whether to build static libraries... yes configure: creating libtool appending configuration tag "CXX" to libtool checking for ld used by g++... /usr/i486-slackware-linux/bin/ld checking if the linker (/usr/i486-slackware-linux/bin/ld) is GNU ld... yes checking whether the g++ linker (/usr/i486-slackware-linux/bin/ld) supports shared libraries... yes checking for g++ option to produce PIC... -fPIC checking if g++ PIC flag -fPIC works... yes checking if g++ static flag -static works... yes checking if g++ supports -c -o file.o... yes checking whether the g++ linker (/usr/i486-slackware-linux/bin/ld) supports shared libraries... yes checking dynamic linker characteristics... GNU/Linux ld.so checking how to hardcode library paths into programs... immediate appending configuration tag "F77" to libtool checking if libtool supports shared libraries... yes checking whether to build shared libraries... yes checking whether to build static libraries... yes checking for g77 option to produce PIC... -fPIC checking if g77 PIC flag -fPIC works... yes checking if g77 static flag -static works... no checking if g77 supports -c -o file.o... yes checking whether the g77 linker (/usr/i486-slackware-linux/bin/ld) supports shared libraries... yes checking dynamic linker characteristics... GNU/Linux ld.so checking how to hardcode library paths into programs... immediate checking for perl5... no checking for perl... /usr/bin/perl checking for courier-config... no checking for expect... /usr/bin/expect checking for passwd... /usr/bin/passwd checking whether -lm is needed for floor... yes checking for socket in -lsocket... no checking for socket in -lsocket... (cached) no checking for connect in -lsocket... no checking for connect in -lsocket... (cached) no checking for gdbm_open in -lgdbm... yes checking for gdbm_open... yes checking for dbopen in -ldb... no checking for db_open in -ldb... no checking for db_env_create in -ldb... yes checking for dbopen... no checking for db_open... no checking for db_env_create... yes checking stdio.h usability... yes checking stdio.h presence... yes checking for stdio.h... yes checking security/pam_appl.h usability... no checking security/pam_appl.h presence... no checking for security/pam_appl.h... no checking Pam/pam_appl.h usability... no checking Pam/pam_appl.h presence... no checking for Pam/pam_appl.h... no checking lber.h usability... yes checking lber.h presence... yes checking for lber.h... yes checking ldap.h usability... yes checking ldap.h presence... yes checking for ldap.h... yes checking netinet/in.h usability... yes checking netinet/in.h presence... yes checking for netinet/in.h... yes checking for endpwent... yes checking shadow.h usability... yes checking shadow.h presence... yes checking for shadow.h... yes checking for getspent in -lshadow... no checking for endspent... yes checking for getspent... yes

---------------------------------------------------- NOTE

All questions regarding ANY vpopmail-related problems, such as compiling/building failures, or login errors should be referred to the vpopmail mailing list. Vpopmail questions sent to the Courier mailing lists will be IGNORED.

----------------------------------------------------

checking for open_smtp_relay... no checking for vset_lastauth... yes checking for pg_config... no checking for mysql_config... /usr/bin/mysql_config checking for ANSI C header files... (cached) yes checking for sys/wait.h that is POSIX.1 compatible... yes checking for sys/stat.h... (cached) yes checking sys/time.h usability... yes checking sys/time.h presence... yes checking for sys/time.h... yes checking for sys/wait.h... (cached) yes checking sys/select.h usability... yes checking sys/select.h presence... yes checking for sys/select.h... yes checking for unistd.h... (cached) yes checking fcntl.h usability... yes checking fcntl.h presence... yes checking for fcntl.h... yes checking crypt.h usability... yes checking crypt.h presence... yes checking for crypt.h... yes checking termios.h usability... yes checking termios.h presence... yes checking for termios.h... yes checking for an ANSI C-conforming const... yes checking for pid_t... yes checking for uid_t in sys/types.h... yes checking return type of signal handlers... void checking for setsid... yes checking for setlogin... no checking for crypt in -lcrypt... yes checking for crypt... yes checking for crypt() prototype... 0 Cannot obtain information for user vpopmai: Success

If you think that courier does not support vpopmail backend you should remove vpopmail support from source.