Same with me. I've forwarded all messages to report@phishing.gov.uk. The tenderapp.com site looks out of date so it may be disused and has been hacked.
Try using a filter. On the vm mail web page, go to Settings, Email, Filter rules. You can set a Condition e.g. Sender contains tenderapp.com. Then set an Action e.g. Reject.
I've added a rule but ill have to wait to see it it works