Disable Indexing for Specific File Types
It may be necessary to disable attachment indexing for specific mimetypes if conversion is unable to process the attachments due to size or other error. When disabled, conversion will be bypassed for only specified mimetypes. Attachment indexing can be disabled for all types if desired. Zimbra Collaboration Suite for Mac OS X currently does not support attachment indexing.
If conversion (convertd) is unable to process certain attachments, messages containing those attachments will queue in the MTA deferred queue. Here are some relevant errors.
Nov 27 01:26:12 ubu03 postfix/lmtp: D3058C9F40: to=<email@example.com>, relay=ubu03.zmb.moc[192.168.5.63], delay=34, status=deferred (host ubu03.zmb.moc[192.168.5.63] said: 451 4.0.0 Temporary message delivery failure try again (in reply to end of DATA command))
2007-11-27 01:26:12,533 WARN [LmtpServer-1]  ParsedMessage - Message had parse errors in 1 parts (Message-Id: <44BB8AB2-8BDE-4AE1-96DC-6A7A2C029924@zmb.moc>, Subject: attachment) 2007-11-27 01:26:12,586 WARN [LmtpServer-1]  ZimbraLmtpBackend - Exception delivering mail (temporary failure) com.zimbra.common.service.ServiceException: system failure: failed to analyze part ... Caused by: com.zimbra.cs.convert.ConversionException: Communication with convertd timed out ... Caused by: java.net.SocketTimeoutException: Read timed out
- 15990 attachment crashes convertd
- 16454 Convertd failing on attachments - messages sent to deferred queue
- 17611 refine attachment handing for non-document types and large file sizes
Disabling Attachment Indexing
All attachment indexing can be disabled at the class of service (COS) or account level. Check "Disable attachment viewing from web mail UI" on the advanced tab of the COS or account you wish to disable indexing.
$ zmprov mc default zimbraAttachmentsIndexingEnabled FALSE
$ zmprov ma firstname.lastname@example.org zimbraAttachmentsIndexingEnabled FALSE
Disabling indexing for certain mimetypes requires direct modification to the Zimbra directory. The goal is to map the desired file extension and mimetype to UnknownTypeHandler as opposed to DefaultHandler. To configure, create an LDIF file, then use ldapadd to apply the changes to LDAP. The following example disables indexing on Visio and AutoCad attachments.
# application/acad, mime, config, zimbra dn: cn=application/acad,cn=mime,cn=config,cn=zimbra zimbraMimeType: application/acad objectClass: zimbraMimeEntry zimbraMimeIndexingEnabled: TRUE zimbraMimeHandlerClass: UnknownTypeHandler zimbraMimeFileExtension: dwg # application/vnd.visio, mime, config, zimbra dn: cn=application/vnd.visio,cn=mime,cn=config,cn=zimbra zimbraMimeType: application/vnd.visio objectClass: zimbraMimeEntry zimbraMimeIndexingEnabled: TRUE zimbraMimeHandlerClass: UnknownTypeHandler zimbraMimeFileExtension: vsd # some clients will send binaries as application/octet-stream type dn: cn=application/octet-stream,cn=mime,cn=config,cn=zimbra cn: application/octet-stream objectclass: zimbraMimeEntry zimbraMimeIndexingEnabled: TRUE zimbraMimeType: application/octet-stream zimbraMimeFileExtension: vsd zimbraMimeFileExtension: dwg zimbraMimeHandlerClass: UnknownTypeHandler description: Disabled application/octet-stream extensions
$ ldapadd -x -h `zmhostname` -D uid=zimbra,cn=admins,cn=zimbra -W -f /tmp/mimedisable.ldif
A service restart is not required after applying the changes.
Verify bypassed attachment types are deliverable.
Keywords: conversion, attachment, indexing, kvoop, verity, mime