When attempting to submit a spam false positive sample the portal issues you with an error message.
You may see one of the following errors
Cause
The False Positive submission portal only allows samples in a message/rfc822 format in an .eml or .msg file type. Any other format submission to the portal is rejected.
The sample you have submitted is over 5MB in size. The False Positive Submission Portal will only allow submission under 5MB.
Environment
ClientNet
Resolution
When submitting a sample for investigation
Ensure any sample that is submitted meets the message/rfc822 standard and is in either a .msg or .eml format.