Found the following messages in my stderr.log :
2011-05-09 17:00:00.371 [STDERR] 537 /home/gwang/release/httpd/httpd/util/vmembuf.cpp: No such file or directory.
2011-05-09 17:00:00.371 [STDERR] sh: mailx: command not found
2011-05-09 17:00:01.667 [STDERR] 537 /home/gwang/release/httpd/httpd/util/vmembuf.cpp: No such file or directory.
2011-05-09 17:00:01.667 [STDERR] sh: mailx: command not found
2011-05-09 17:00:45.430 [STDERR] 537 /home/gwang/release/httpd/httpd/util/vmembuf.cpp: No such file or directory.
2011-05-09 17:00:45.506 [STDERR] sh: mailx: command not found
2011-05-09 17:00:46.233 [STDERR] 537 /home/gwang/release/httpd/httpd/util/vmembuf.cpp: No such file or directory.
2011-05-09 17:00:46.309 [STDERR] sh: mailx: command not found
2011-05-09 17:00:50.067 [STDERR] 537 /home/gwang/release/httpd/httpd/util/vmembuf.cpp: No such file or directory.
2011-05-09 17:00:50.143 [STDERR] sh: mailx: command not found
2011-05-09 17:00:00.371 [STDERR] 537 /home/gwang/release/httpd/httpd/util/vmembuf.cpp: No such file or directory.
2011-05-09 17:00:00.371 [STDERR] sh: mailx: command not found
2011-05-09 17:00:01.667 [STDERR] 537 /home/gwang/release/httpd/httpd/util/vmembuf.cpp: No such file or directory.
2011-05-09 17:00:01.667 [STDERR] sh: mailx: command not found
2011-05-09 17:00:45.430 [STDERR] 537 /home/gwang/release/httpd/httpd/util/vmembuf.cpp: No such file or directory.
2011-05-09 17:00:45.506 [STDERR] sh: mailx: command not found
2011-05-09 17:00:46.233 [STDERR] 537 /home/gwang/release/httpd/httpd/util/vmembuf.cpp: No such file or directory.
2011-05-09 17:00:46.309 [STDERR] sh: mailx: command not found
2011-05-09 17:00:50.067 [STDERR] 537 /home/gwang/release/httpd/httpd/util/vmembuf.cpp: No such file or directory.
2011-05-09 17:00:50.143 [STDERR] sh: mailx: command not found