Thanks for the comments.
I ask as sometimes an email (from a professional/company) might be received from their private email address, or there may have been some problem with the jpeg attachment which contains the relevant company details, and so on.
The traceability thing is interesting, as many people do not have a dedicated email address such as 'susan at companyname.ie , and are instead using susan at gmail, hotmail or whatever.
On a related topic, I presume professional advice or comment contained in a text message is also viable as evidence?