Sellers are not required to give any reasons as to why they canceled bids on an item.
Ebay has a policy about what to do if you are receiving harassing emails from another member. It contails a link to report the member.
Here's some information that might help
If another member sends you inappropriate emails, such as spam, threats of physical harm, or messages with profanity or hate speech, contact us. You should also report any serious threats to local law enforcement.
Members who violate our member-to-member contact policy may face:
Limits on account privilegesAccount suspensionForfeit of eB...