After upgrading from 3.1 GA to the new 3.1.1 on debian, I'm receiving the following message when pressing the send mail button on the web ui. As far as I know nothing changed except for the upgrade. I am using a relay host (local isp) for smtp mail delivery.

Code:
msg - SMTP server reported: 452 Message rejected
com.zimbra.cs.mailbox.MailServiceException: SMTP server reported: 452 Message rejected
	at com.zimbra.cs.mailbox.MailServiceException.internal_SEND_FAILURE(MailServiceException.java:337)
	at com.zimbra.cs.mailbox.MailServiceException.SEND_FAILURE(MailServiceException.java:349)
	at com.zimbra.cs.mailbox.MailSender.sendMimeMessage(MailSender.java:298)
	at com.zimbra.cs.mailbox.MailSender.sendMimeMessage(MailSender.java:122)
	at com.zimbra.cs.service.mail.SendMsg.handle(SendMsg.java:97)
	at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEngine.java:255)
	at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.java:163)
	at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.java:84)
	at com.zimbra.soap.SoapServlet.doPost(SoapServlet.java:228)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
	at com.zimbra.cs.servlet.ZimbraServlet.service(ZimbraServlet.java:154)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:541)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
	at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:667)
	at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
	at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
	at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
	at java.lang.Thread.run(Thread.java:595)
Caused by: com.sun.mail.smtp.SMTPSendFailedException: 452 Message rejected

	at com.sun.mail.smtp.SMTPTransport.issueSendCommand(SMTPTransport.java:1333)
	at com.sun.mail.smtp.SMTPTransport.mailFrom(SMTPTransport.java:906)
	at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:535)
	at javax.mail.Transport.send0(Transport.java:151)
	at javax.mail.Transport.send(Transport.java:80)
	at com.zimbra.cs.mailbox.MailSender.sendMimeMessage(MailSender.java:199)
	... 24 more

code - mail.SEND_FAILURE
method - ZmCsfeCommand.prototype.invoke
detail - soap:Sender
data - [object Object]