Postage standard mail headers

To recognize its own mails, Postage adds a couple of headers to its test mails. AbstractMailFactory takes care for adding those headers correctly.

X-James-Postage=This is a test mail sent by James Postage

X-James-Postage-Count=1158086107828-1 where "1158086107828" is constant for the whole scenario run while "1" is incremented with every test mail.

X-James-Postage-Count=PROFORMA is used for all mails in the startup phase.

Message-ID=Postage-1158086175218 where "1158086175218" is a time stamp distinguishing this mail from all others.

X-James-Validator=org.apache.james.postage.mail.AbstractMailFactory

These headers are used for identifying, matching and validating test mails. If headers are missing, the result report can not be build properly.