Boxtrapper letting spam through when verification mail bounces

Hello folks,

I'm not sure how to solve this problem, but when the verification email from boxtrapper bounces due to email address being spoofed, I receive the bounced verification email plus a separate copy of the spam email.

When I look in the queue within boxtrapper the spam email is there waiting for verification, but I've already received it!

The boxtrapper log contains this report -

I hope someone can advise what might be going wrong.

Myles