$ zmcontrol start
Host mail.x.org
Starting logger...Done.
Starting mailbox...Done.
Starting antispam...Done.
Starting antivirus...Done.
Starting snmp...Done.
Starting spell...Done.
Starting mta...FAILED
/opt/zimbra/cyrus-sasl-2.1.21.ZIMBRA/sbin/saslauthd: error while loading shared libraries: libcurl.so.3: cannot open shared object file: No such file or directory
zmsaslauthdctl failed to start

I only have libcurl.so.2 and libcurl.so.4. How can I install libcurl.so.3? I am using 32-bit os.