If they are all in the same Inbox, then probably no. An email client knows little about a message until it is downloaded, so probably can't differentiate between the messages prior to downloading them. I'd suggest running server-side filtering to move them into appropriate folders, but to gain access to those folders you'd need to be using IMAP. And you have either chosen not to use IMAP, or it isn't offered by your email provider? Or download just the headers and see if you can use a Thunderbird Message Filter to fetch the body of the message, or not, as appropriate. But that probably won't stop the unwanted messages appearing in your Inbox, even though incomplete. Can you not use real discrete email addresses? Aliases seem to be a continual source of annoyance.