I recently installed Desktp 2.0.1 (build 10659) in a Ubuntu lucyd box.
Right clicking on a local folder, line "Share folder" is disabled; so, I select "Edit properties" and a "Folder properties" popup opens. I select on "Add Share" and select: "Share with internal users or groups", "Role manager"; in the email box I type the email of a Zimbra user; clicking on OK button, I get:

"An unknown error (mail.TRY_AGAIN) has occurred."

clicking on "Show Details", I can see:

An unknown error (mail.TRY_AGAIN) has occurred.
method: SendMsgRequest
msg: try again: Unable to connect to the MTA
code: mail.TRY_AGAIN
detail: soap:Receiver
trace: com.zimbra.cs.mailbox.MailServiceException: try again: Unable to connect to the MTA ExceptionId:btpool0-8:1296151553219:ea5db079d51a8f85 Code:mail.TRY_AGAIN at com.zimbra.cs.mailbox.MailServiceException.TRY_AGA IN(MailServiceException.java:475) at com.zimbra.cs.mailbox.MailSender.sendMimeMessage(M ailSender.java:537) at com.zimbra.cs.mailbox.MailSender.sendMimeMessage(M ailSender.java:371) at com.zimbra.cs.mailbox.MailSender.sendMimeMessage(M ailSender.java:328) at com.zimbra.cs.service.mail.SendMsg.doSendMessage(S endMsg.java:189) at com.zimbra.cs.service.mail.SendMsg.handle(SendMsg. java:150) at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEng ine.java:420) at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:274) at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:158) at com.zimbra.soap.SoapServlet.doWork(SoapServlet.jav a:291) at com.zimbra.soap.SoapServlet.doPost(SoapServlet.jav a:212) at javax.servlet.http.HttpServlet.service(HttpServlet .java:727) at com.zimbra.cs.servlet.ZimbraServlet.service(Zimbra Servlet.java:181) at javax.servlet.http.HttpServlet.service(HttpServlet .java:820) at org.mortbay.jetty.servlet.ServletHolder.handle(Ser vletHolder.java:511) at org.mortbay.jetty.servlet.ServletHandler.handle(Se rvletHandler.java:390) at org.mortbay.jetty.security.SecurityHandler.handle( SecurityHandler.java:216) 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:418) 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.Server.handle(Server.java:326) at org.mortbay.jetty.HttpConnection.handleRequest(Htt pConnection.java:543) at org.mortbay.jetty.HttpConnection$RequestHandler.co ntent(HttpConnection.java:939) at org.mortbay.jetty.HttpParser.parseNext(HttpParser. java:755) at org.mortbay.jetty.HttpParser.parseAvailable(HttpPa rser.java:218) at org.mortbay.jetty.HttpConnection.handle(HttpConnec tion.java:405) at org.mortbay.io.nio.SelectChannelEndPoint.run(Selec tChannelEndPoint.java:413) at org.mortbay.thread.BoundedThreadPool$PoolThread.ru n(BoundedThreadPool.java:451) Caused by: java.net.ConnectException: Connection refused at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.PlainSocketImpl.doConnect(Unknown Source) at java.net.PlainSocketImpl.connectToAddress(Unknown Source) at java.net.PlainSocketImpl.connect(Unknown Source) at java.net.SocksSocketImpl.connect(Unknown Source) at java.net.Socket.connect(Unknown Source) at com.sun.mail.util.SocketFetcher.createSocket(Socke tFetcher.java:265) at com.sun.mail.util.SocketFetcher.getSocket(SocketFe tcher.java:227) at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTra nsport.java:1511) at com.sun.mail.smtp.SMTPTransport.protocolConnect(SM TPTransport.java:453) at javax.mail.Service.connect(Service.java:291) at javax.mail.Service.connect(Service.java:172) at javax.mail.Service.connect(Service.java:121) at com.zimbra.cs.mailbox.MailSender.sendMessageToHost (MailSender.java:843) at com.zimbra.cs.mailbox.MailSender.sendMessage(MailS ender.java:764) at com.zimbra.cs.mailbox.MailSender.sendMimeMessage(M ailSender.java:474) ... 31 more
request:

Body: {
SendMsgRequest: {
_jsns: "urn:zimbraMail",
m: {
e: [
0: {
a: "mcecchi@cesip.priv",
add: "0",
t: "t"
}
],
mp: [
0: {
ct: "multipart/alternative",
mp: [
0: {
content: {
_content: "The following share has been created:

Shared item: condivisa locale (Mail Folder)
Owner: local@host.local

Grantee: mcecchi@cesip.priv
Role: Viewer
Allowed actions: View
"
},
ct: "text/plain"
},
1: {
content: {
_content: "<h3>The following share has been created:</h3>
<p>
<table border="0">
<tr><th align="left">Shared item:</th><td>condivisa locale (Mail Folder)</td></tr>
<tr><th align="left">Owner:</th><td>local@host.local</td></tr>
</table>
</p>
<table border="0">
<tr><th align="left">Grantee:</th><td>mcecchi@cesip.priv</td></tr>
<tr><th align="left">Role:</th><td>Viewer</td></tr>
<tr><th align="left">Allowed actions:</th><td>View</td>
</tr>
</table>"
},
ct: "text/html"
},
2: {
content: {
_content: "<share xmlns="urn:zimbraShare" version="0.1" action="new" >
<grantee id="undefined" email="mcecchi@cesip.priv" name="mcecchi@cesip.priv" />
<grantor id="ffffffff-ffff-ffff-ffff-ffffffffffff" email="local@host.local" name="local@host.local" />
<link id="560" name="condivisa locale" view="message" perm="r" />
<notes></notes>
</share>"
},
ct: "xml/x-zimbra-share"
}
]
}
],
su: {
_content: "Share Created: condivisa locale shared by local@host.local"
}
}
}
},
Header: {
context: {
_jsns: "urn:zimbra",
account: {
_content: "local@host.local",
by: "name"
},
authToken: "(removed)",
session: {
_content: 124,
id: 124
},
userAgent: {
name: "ZimbraWebClient - PRISM (Linux)",
version: "0.0"
}
}
}

No further log on server side (a CentOS 5.5 box running zcs-6.0.10_GA_2692.RHEL5_64) in /opt/zimbra log.

Any idea?

Aldobenart