webMethods Developer Question

We have a requirement to create a service request in the company service management system.
The details are contained in the email body with additional info contained in attachments. eg pictures,
word documents, pdf etc…

What we’ve got

* the email has a specific subject line, which is the service to be invoked

The behaviour we’re experiencing

* The service is invoked multiple times for each email
* each invocation only having ONE part of the email in the payload
o either text
o or one each per attachment
* for example if an email with 2 attachments is recieved
o The service is called once with the text content and a mime-type of multipart
o 2 more times each with the mime-type of the attached file and it's content
o for a total of 3 calls to the service

The problem

* the call does not carry any identity/guid/.... information
* there is no obvious way to correlate these 3 calls into one transaction.
* remember i need to create one service call with the details from the text and attach all/each of the attachments as sundry information to the call.

How would you advise the correlation should be done? can i also request that an id be created when an email is recieved and carried through so the various parts
can be identified/correlated much like the envelope of broker documents.
Thanx