When submitting a spam mail to firstname.lastname@example.org it's important that you do not forward the mail in question. If you forward the mail the headers are removed, and the headers contain a lot of diagnostic information we can use in the analysis of the mail. To preserve the headers you need to export the mail from your mail client and send us the .eml or .msg file created.
To export an email from the Outlook mail client you can:
1: Left click and hold on the mail in question and drag it from your mailbox to the desktop. This will create a .msg file containing the entire mail headers and body.
2. Attach the .msg file to a mail and sent it to email@example.com
The Mozilla Thunderbird mail client works the same way except the file created is a .eml file.