Another crahs with backtrace:
GNU gdb 6.8-debian
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later http://gnu.org/licenses/gpl.html
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "i486-linux-gnu"...
Reading symbols from /lib/i686/cmov/libcrypt.so.1...Reading symbols from /usr/lib/debug/lib/i686/cmov/libcrypt-2.9.so...done.
done.
Loaded symbols for /lib/i686/cmov/libcrypt.so.1
Reading symbols from /lib/libpam.so.0...done.
Loaded symbols for /lib/libpam.so.0
Reading symbols from /lib/i686/cmov/libdl.so.2...Reading symbols from /usr/lib/debug/lib/i686/cmov/libdl-2.9.so...done.
done.
Loaded symbols for /lib/i686/cmov/libdl.so.2
Reading symbols from /lib/i686/cmov/libc.so.6...Reading symbols from /usr/lib/debug/lib/i686/cmov/libc-2.9.so...done.
done.
Loaded symbols for /lib/i686/cmov/libc.so.6
Reading symbols from /lib/ld-linux.so.2...Reading symbols from /usr/lib/debug/lib/ld-2.9.so...done.
done.
Loaded symbols for /lib/ld-linux.so.2
Reading symbols from /lib/i686/cmov/libnss_compat.so.2...Reading symbols from /usr/lib/debug/lib/i686/cmov/libnss_compat-2.9.so...done.
done.
Loaded symbols for /lib/i686/cmov/libnss_compat.so.2
Reading symbols from /lib/i686/cmov/libnsl.so.1...Reading symbols from /usr/lib/debug/lib/i686/cmov/libnsl-2.9.so...done.
done.
Loaded symbols for /lib/i686/cmov/libnsl.so.1
Reading symbols from /lib/i686/cmov/libnss_nis.so.2...Reading symbols from /usr/lib/debug/lib/i686/cmov/libnss_nis-2.9.so...done.
done.
Loaded symbols for /lib/i686/cmov/libnss_nis.so.2
Reading symbols from /lib/i686/cmov/libnss_files.so.2...Reading symbols from /usr/lib/debug/lib/i686/cmov/libnss_files-2.9.so...done.
done.
Loaded symbols for /lib/i686/cmov/libnss_files.so.2
Reading symbols from /lib/libgcc_s.so.1...done.
Loaded symbols for /lib/libgcc_s.so.1
Core was generated by `dovecot-auth'.
Program terminated with signal 6, Aborted.
[New process 7692]
#0 0xb8071424 in __kernel_vsyscall ()
#0 0xb8071424 in __kernel_vsyscall ()
No symbol table info available.
#1 0xb7eee680 in *__GI_raise (sig=6)
at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
resultvar = <value optimized out>
pid = -1207832588
selftid = 7692
#2 0xb7ef1d68 in *__GI_abort () at abort.c:88
act = {__sigaction_handler = {sa_handler = 0x8f90618,
sa_sigaction = 0x8f90618}, sa_mask = {__val = {3220762632, 134653482,
3087132384, 0, 3220762752, 3220762740, 512, 0, 0, 3220762816,
3087595120, 134536646, 541, 0, 0, 0, 1, 134703806, 512, 1, 3220762740,
150537720, 69, 3220762868, 3220762712, 134655078, 150538293, 3220762740,
3220762744, 542, 150537752, 3086574819}}, sa_flags = 542,
sa_restorer = 0x807af69
----- End forwarded message -----
-- Ralf Hildebrandt Postfix - Einrichtung, Betrieb und Wartung Tel. +49 (0)30-450 570-155 http://www.computerbeschimpfung.de
From empirical experience, your Exchange admin needs to put down the crack pipe and open a window to disperse the fumes.