You might consider creating a filter that looks for your email account in FROM and also in TO and delete them.

I get plenty of those types of bogus mail. You are wary of using your email address to set up as spam. I agree because if you are using an imap account then that sort of information - put in Spam folder - is also then known by the server and it can be used to 'complain' about the email address. Thus you could inadvertantly end up getting your own email address on server spam filters.

In addition you do need to careful that you do not end up wth a filter that does not realise the From is from you testing something. Never use TO your email address because everything you get is TO you.

I have found that in many cases there is a 'Repy-to' which maybe a common factor and can be used in the filter. Sometimes you can use the 'Subject' content in a filter. maybe there is the original IP address in the 'Received by' headers but again you need to be careful because they maybe using a VPN, so not exactly reliable.

Select email - click on 'More' and select 'View Source' OR Close the Message Pane - select email in list to highlight - View > Message Source or (Ctrl+U) This offers more data on what is contained in the email.

Sometimes this is something that's temporary - the nefarious person is looking for people to respond or click on something in the email which triggers some remote content in email. Just make sure you have the default do not allow remote content selected - Thunderbird does set that by default. Don't click on anything that may be in that email. Basically, if you know it's not you then just delete it. They usually get bored after a while when there is no response.