I have several mail lists (e.g. any list that is from Yahoo Groups or the sender uses a tool to insert advertising in the email messages it sends) & would like to remove this from the message base stored on my computer. I have had good success at blocking this garbage when I use Firefox but need something that works with Thunderbird. I cannot say there is not already an add-on for Thunderbird, but if there is. I have yet to find it. I do not object to writing my own pattern matches but have no idea how to integrate this into Thunderbird. From the searches I have done so far, it appears that uBlock Origin used to work with Thunderbird but the format for add-ons within Thunderbird has changed & have seen several warnings about it for this reason. I am slowly migrating from uBlock Origin to AdGuard as uBlock Origin does not seem to be available on handheld devices while AdGuard is (sorry but as I copy/paste filter elements between platforms it is easier with 1 tool.) Any suggestions on this subject would be appreciated.