zmcontrol -v
Release 7.1.2_GA_3268.UBUNTU10_64 UBUNTU10_64 NETWORK edition.
This for us, is a two part issue. The non display of the signature, and the break in functionality.
Occasionally (appears to relate to who the sender is/their server software/their email client/havent worked it out yet, but so far these are the only differences I can find) apon recieving an email, the senders signature end up as an attachment. This attachment is always labelled 'Unknown <text/html>' we know its the signature as when we open it (clicking on the file name) we can see the signature.
This in turn seems to break the ability to Download all attachments. On clicking download all, nothing happens, the web client just waits indefinitely. This only happens on emails that have the signature as an Unknown attachment. When attempting to remove the attachment, it presents us:
No such message part exists.
method: [unknown]
msg: no such message part: 2.2.1
code: mail.NO_SUCH_PART
detail: soap:Sender
trace: com.zimbra.cs.mailbox.MailServiceException: no such message part: 2.2.1 ExceptionId:btpool0-11427://zimbra._munged_/service/soap/RemoveAttachmentsRequest:1315191397572:09023a14dc7 61049 Code:mail.NO_SUCH_PART Arg
name, STR, "2.2.1") at com.zimbra.cs.mailbox.MailServiceException.NO_SUCH _PART(MailServiceException.java:173) at com.zimbra.cs.service.mail.RemoveAttachments.strip Part(RemoveAttachments.java:160) at com.zimbra.cs.service.mail.RemoveAttachments.handl e(RemoveAttachments.java:76) at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEng ine.java:412) at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:287) at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:158) at com.zimbra.soap.SoapServlet.doWork(SoapServlet.jav a:294) at com.zimbra.soap.SoapServlet.doPost(SoapServlet.jav a:215) at javax.servlet.http.HttpServlet.service(HttpServlet .java:725) at com.zimbra.cs.servlet.ZimbraServlet.service(Zimbra Servlet.java:208) at javax.servlet.http.HttpServlet.service(HttpServlet .java:814) at org.mortbay.jetty.servlet.ServletHolder.handle(Ser vletHolder.java:511) at org.mortbay.jetty.servlet.ServletHandler$CachedCha in.doFilter(ServletHandler.java:1166) at com.zimbra.cs.servlet.SetHeaderFilter.doFilter(Set HeaderFilter.java:79) at org.mortbay.jetty.servlet.ServletHandler$CachedCha in.doFilter(ServletHandler.java:1157) at org.mortbay.servlet.UserAgentFilter.doFilter(UserA gentFilter.java:81) at org.mortbay.servlet.GzipFilter.doFilter(GzipFilter .java:132) at org.mortbay.jetty.servlet.ServletHandler$CachedCha in.doFilter(ServletHandler.java:1157) at org.mortbay.jetty.servlet.ServletHandler.handle(Se rvletHandler.java:388) at org.mortbay.jetty.security.SecurityHandler.handle( SecurityHandler.java:218) at org.mortbay.jetty.servlet.SessionHandler.handle(Se ssionHandler.java:182) at org.mortbay.jetty.handler.ContextHandler.handle(Co ntextHandler.java:765) at org.mortbay.jetty.webapp.WebAppContext.handle(WebA ppContext.java:422) at org.mortbay.jetty.handler.ContextHandlerCollection .handle(ContextHandlerCollection.java:230) at org.mortbay.jetty.handler.HandlerCollection.handle (HandlerCollection.java:114) at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:152) at org.mortbay.jetty.handler.rewrite.RewriteHandler.h andle(RewriteHandler.java:230) at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:152) at org.mortbay.jetty.handler.DebugHandler.handle(Debu gHandler.java:77) at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:152) at org.mortbay.jetty.Server.handle(Server.java:326) at org.mortbay.jetty.HttpConnection.handleRequest(Htt pConnection.java:543) at org.mortbay.jetty.HttpConnection$RequestHandler.co ntent(HttpConnection.java:946) at org.mortbay.jetty.HttpParser.parseNext(HttpParser. java:756) at org.mortbay.jetty.HttpParser.parseAvailable(HttpPa rser.java:218) at org.mortbay.jetty.HttpConnection.handle(HttpConnec tion.java:405) at org.mortbay.io.nio.SelectChannelEndPoint.run(Selec tChannelEndPoint.java:410) at org.mortbay.thread.BoundedThreadPool$PoolThread.ru n(BoundedThreadPool.java:451)
request:
Body: {
RemoveAttachmentsRequest: {
_jsns: "urn:zimbraMail",
m: {
id: "55192",
part: "2.2.1"
}
}
},
Header: {
context: {
_jsns: "urn:zimbra",
account: {
_content: "brad@_munged_",
by: "name"
},
authToken: "(removed)",
session: {
_content: 1150679,
id: 1150679
},
userAgent: {
name: "ZimbraWebClient - FF3.0 (Linux)",
version: "7.1.2_GA_3268"
}
}
}
Any help would be appreciated.
Bugzilla
Wiki
Source
Signatures coming through as attachment, breaking download all functionality. 
Having the same issue.... 
reproduced and filed a bug... 
Linear Mode
