Most of the genuine advertising I get is from real businesses. If you really don't want their traffic, do us all a favour and consider unsubscribing from their newsletters and what have you; you'll free up a tiny amount of wasted internet bandwidth. If these messages are truly unsolicited, then mark them as Junk and train Thunderbird's Junk Controls to deal with them. For stuff that is generally of little or no interest, and does no harm, but for various reasons I'd be reluctant to sever my ties to them, I use an address book called ''cruft'' and I set up a folder named ''cruft''. My filter looks to see if the sender appears in my ''cruft'' address book, and if so, moves the message to the ''cruft'' folder. I review this occasionally and manually delete most of it. I also occasionally sweep it for addresses and add them to the ''cruft'' address book. Note that some legitimate posters, who really ought to know better, use randomised "local parts" (i.e. the bit before the '@') and so you can't just pop these addresses into the ''cruft'' address book. For these I have to set up a second filter which filters on "sender/ends with" so as to filter on the domains. Certain senders do send something useful amongst the dross. Amazon, for one, where I am happy to get notifications about the progress of my orders, but don't particularly want to see the suggestions and requests for feedback. So the latter addresses are put into the cruft address book, and the useful ones actively filtered to the amazon folder. So, now you need to set up some filters. https://support.mozilla.org/en-US/kb/organize-your-messages-using-filters