Done.
locate libmysqlclient.so.16
[root@s18147502 ~]# ldd /usr/sbin/postconf
linux-vdso.so.1 => (0x00007ffe43bf8000)
libsasl2.so.2 => /usr/lib64/libsasl2.so.2 (0x00007f4fa790e000)
libpcre.so.0 => /lib64/libpcre.so.0 (0x00007f4fa76e1000)
libmysqlclient.so.16 => not found
libz.so.1 => /lib64/libz.so.1 (0x00007f4fa74ca000)
libm.so.6 => /lib64/libm.so.6 (0x00007f4fa7246000)
libssl.so.10 => /usr/lib64/libssl.so.10 (0x00007f4fa6fd9000)
libcrypto.so.10 => /usr/lib64/libcrypto.so.10 (0x00007f4fa6bf6000)
libdb-4.7.so => /lib64/libdb-4.7.so (0x00007f4fa6882000)
libnsl.so.1 => /lib64/libnsl.so.1 (0x00007f4fa6668000)
libresolv.so.2 => /lib64/libresolv.so.2 (0x00007f4fa644e000)
libc.so.6 => /lib64/libc.so.6 (0x00007f4fa60ba000)
libdl.so.2 => /lib64/libdl.so.2 (0x00007f4fa5eb5000)
libcrypt.so.1 => /lib64/libcrypt.so.1 (0x00007f4fa5c7e000)
libgssapi_krb5.so.2 => /lib64/libgssapi_krb5.so.2 (0x00007f4fa5a3a000)
libkrb5.so.3 => /lib64/libkrb5.so.3 (0x00007f4fa5752000)
libcom_err.so.2 => /lib64/libcom_err.so.2 (0x00007f4fa554e000)
libk5crypto.so.3 => /lib64/libk5crypto.so.3 (0x00007f4fa5322000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f4fa5104000)
/lib64/ld-linux-x86-64.so.2 (0x00007f4fa7d9b000)
libfreebl3.so => /lib64/libfreebl3.so (0x00007f4fa4f01000)
libkrb5support.so.0 => /lib64/libkrb5support.so.0 (0x00007f4fa4cf6000)
libkeyutils.so.1 => /lib64/libkeyutils.so.1 (0x00007f4fa4af2000)
libselinux.so.1 => /lib64/libselinux.so.1 (0x00007f4fa48d3000)
locate libmysqlclient.so.16
[root@s18147502 ~]# ldd /usr/sbin/postconf
linux-vdso.so.1 => (0x00007ffe43bf8000)
libsasl2.so.2 => /usr/lib64/libsasl2.so.2 (0x00007f4fa790e000)
libpcre.so.0 => /lib64/libpcre.so.0 (0x00007f4fa76e1000)
libmysqlclient.so.16 => not found
libz.so.1 => /lib64/libz.so.1 (0x00007f4fa74ca000)
libm.so.6 => /lib64/libm.so.6 (0x00007f4fa7246000)
libssl.so.10 => /usr/lib64/libssl.so.10 (0x00007f4fa6fd9000)
libcrypto.so.10 => /usr/lib64/libcrypto.so.10 (0x00007f4fa6bf6000)
libdb-4.7.so => /lib64/libdb-4.7.so (0x00007f4fa6882000)
libnsl.so.1 => /lib64/libnsl.so.1 (0x00007f4fa6668000)
libresolv.so.2 => /lib64/libresolv.so.2 (0x00007f4fa644e000)
libc.so.6 => /lib64/libc.so.6 (0x00007f4fa60ba000)
libdl.so.2 => /lib64/libdl.so.2 (0x00007f4fa5eb5000)
libcrypt.so.1 => /lib64/libcrypt.so.1 (0x00007f4fa5c7e000)
libgssapi_krb5.so.2 => /lib64/libgssapi_krb5.so.2 (0x00007f4fa5a3a000)
libkrb5.so.3 => /lib64/libkrb5.so.3 (0x00007f4fa5752000)
libcom_err.so.2 => /lib64/libcom_err.so.2 (0x00007f4fa554e000)
libk5crypto.so.3 => /lib64/libk5crypto.so.3 (0x00007f4fa5322000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f4fa5104000)
/lib64/ld-linux-x86-64.so.2 (0x00007f4fa7d9b000)
libfreebl3.so => /lib64/libfreebl3.so (0x00007f4fa4f01000)
libkrb5support.so.0 => /lib64/libkrb5support.so.0 (0x00007f4fa4cf6000)
libkeyutils.so.1 => /lib64/libkeyutils.so.1 (0x00007f4fa4af2000)
libselinux.so.1 => /lib64/libselinux.so.1 (0x00007f4fa48d3000)