When used with a lot of threads, EmailRouter is throwing an exception, it looks like from a null SMTP from address.

[1]    2014-11-13 14:59:25,620 ERROR 
[org.jboss.resource.adapter.jms.inflow.JmsServerSession] Unexpected 
error delivering message SolObjectMessage={ 
JMSCorrelationID:1a7d743a-75e5-4719-aed7-825a50192c64,JMSDeliveryMode:2,JMSDestination:Queue 
'queue/eai-email-queue',JMSExpiration:0,JMSMessageID:ID:10.210.12.618fb4149a877083b0:119130,JMSPriority:0,JMSRedelivered,JMSTimestamp:1415890730845,JMSProperties:{sendTo:EAIUATSupport@lgim.com,subject:UOI 
Mismatch from Phoenix [Realtime 
Instrument],from:u00_esb@lgim.co.uk,JMS_Solace_DeliverToOne:false,JMS_Solace_DeadMsgQueueEligible:true,JMS_Solace_ElidingEligible:false,Solace_JMS_Prop_IS_Reply_Message:false},SolPayload:{Binary 
Attachment:len=3747} }
java.lang.NullPointerException
        at javax.mail.internet.InternetAddress.parse(InternetAddress.java:615)
        at javax.mail.internet.InternetAddress.parse(InternetAddress.java:575)
        at javax.mail.internet.InternetAddress.<init>(InternetAddress.java:107)
        at org.jboss.soa.esb.helpers.Email.addMessageAddressing(Email.java:401)
        at org.jboss.soa.esb.helpers.Email.createMailMessage(Email.java:386)
        at org.jboss.soa.esb.helpers.Email.getMailMessage(Email.java:239)
        at org.jboss.soa.esb.helpers.Email.sendMessage(Email.java:229)
        at 
org.jboss.soa.esb.actions.routing.email.Emailer.sendEmail(Emailer.java:184)
        at 
org.jboss.soa.esb.actions.routing.email.Emailer.sendEmail(Emailer.java:141)
        at 
org.jboss.soa.esb.actions.routing.email.EmailRouter.route(EmailRouter.java:78)
        at 
org.jboss.soa.esb.actions.routing.AbstractRouter.process(AbstractRouter.java:80)
        at 
org.jboss.soa.esb.actions.routing.email.EmailRouter.process(EmailRouter.java:70)
        at 
org.jboss.soa.esb.listeners.message.ActionProcessingPipeline.processPipeline(ActionProcessingPipeline.java:667)
        at 
org.jboss.soa.esb.listeners.message.ActionProcessingPipeline.processPipeline(ActionProcessingPipeline.java:614)
        at 
org.jboss.soa.esb.listeners.message.ActionProcessingPipeline.process(ActionProcessingPipeline.java:442)
        at 
org.jboss.soa.esb.listeners.jca.JcaMessageAwareListener.process(JcaMessageAwareListener.java:163)
        at 
org.jboss.soa.esb.listeners.jca.JcaJMSInflowMessageProcessorAdapter.onMessage(JcaJMSInflowMessageProcessorAdapter.java:44)


From Martin :

Bottom line is that EmailRouter is only thread safe when used in a 
static fashion (all fields defined in jboss-esb.xml). If used 
dynamically, with the fields populated at runtime based on the message
content, it is necessary to limit the thread count to 1 to avoid 
multi-threading issues.

From Kevin : 

I think the problem is in the EmailRouter/Emailer classes.  The EmailRouter shares the ConfigTree however the process method can also alter it depending on the message contents which is not safe.  The Emailer class should be taking into account the message contents but without altering ConfigTree.