Tech Tips: blocking spam in Thunderbird

Thunderbird has very powerful filters - and they work. What it does not have is a pre-defined "block sender" filter, nor a "global filter" facility for those with multiple filters on the desktop.

We can fix the first issue, but so far not the second so if anyone has found out how to do that, let us know.

We have found that one particularly virulent spammer - based in Malaysia but using a domain name issued in China - has been able to bypass our multi-layer (and very aggressive) anti-spam systems in part because they use multiple send names and multiple "before the @ sign" variables. This is not a new trick - but the fact that they always send from the same domain helps us.

We have set up filters that simply deletes any mail from any sender that contains their domain name.

The process is simple:

Tools > Message Filters > New

Name the filter anything you like

Select from the drop down boxes From and contains then enter the domain you wish to kill.

In the lower pane of the box, pick Delete Message from the drop down, then click on OK.

Check the name has appeared in the Filter list, then click on it once. Then click on Run Filter Now.

That will remove any instances that remain in your mailbox before this filter is installed.

Then close the box.

Of course, you will need to do this for each account on your desktop but often individual spammers have only one of your addresses anyway so it's not terribly onerous.