1. Open Thunderbird.
2. On the menu bar click on "Tools" then select "Message Filters..."
3. Click on the "New" button.
4. On the next screen you will create the rule by doing the following:
a. Filter Name: Type in a descriptor for your mail rule. This is how to identify it among any rules you setup
b. For incoming messages that: select the radio button by "Match any of the following"
c. Select "From" from the drop down.
d. Select "contains" from the next drop down.
e. Type in the email address you want to white list (steps c-e are for individual email addresses)
f. If you'd like to expand your white list click on the "+" otherwise skip to step l.
g. Repeat steps c-f for whatever addresses you'd like to add then skip to step l; or if you'd like to white list any addresses from a specific domain while you are at it you can continue to step h.
h. Select "From" from the first drop down.
i. Select "contains" from the second drop down.
j. Enter the domain you want to white list (e.g. @macsales.com). By inputting just a domain any emails that come from that domain will be considered white listed.
k. If you'd like to expand the white list with more domains click on the "+" and repeat steps h-k.
When done move on to step l.
l. Under "Perform these actions:" for the first drop down select "Move Message to"
m. Select "Inbox on Local Folders" from the next drop down.
n. If you'd like to add more domains click the "+" sign and repeat steps l-m. If you are finished proceed to step o.
o. Click the "OK" button
5. It will now show up in your current Message Filters list.
6. It is best to have your white list apply first to incoming messages then any other rules you might have set. The rules you see apply in the order they are in the list. You can adjust the position of your filters by highlighting the one in question and then clicking on the "Move Up" or "Move Down" buttons.
7. Congratulations! You now have a white list mail rule. Do not forget to update it in the future as you get more contacts or domains you want to make an exception for.