From Zimbra :: Wiki
Troubleshooting convertd errors
Convertd problems can also cause errors when importing a file with the Import Wizard.
From time to time convertd may generate many warnings similar to the following in the /opt/zimbra/log/zimbra.log:
2006-11-02 00:31:25,483 WARN [LmtpServer-22]  ParsedMessage - Parse error on MIME part 2 (image/gif, Message-ID: <DQW111-F3632B2C627C811FBE3F22EA1F90@dom.com>) com.zimbra.cs.mime.MimeHandlerException: cannot extract text
These warnings indicate that the conversion system cannot correctly handle an attachment. They are not necessarily indicative of a problem with the configuration of your server or the convertd system. There are many messages that are not parseable by convertd, and those are just ignored without problems.
|Verified Against: unknown||Date Created: 11/2/2006|
|Article ID: http://wiki.zimbra.com/index.php?title=Convertd_Errors||Date Modified: 07/30/2014|