How to set up a filter from inside an email message
Making Filters in Gmail
When you have an email open it is easy to create a Filter to automate the way that Gmail will handle messages like it. First you need to click on the More Button above the message.
Filter messages like these
After you click the More Button you will see a menu that gives you the option "Filter Messages like these".
The search box will allow you to pic the criteria from the email you want to use to search for. You can use email sender, email subject, and even words that may be in the body of the message. The search options are incredibly powerful.
In this example you can see that I am searching for any email that is from the email address: firstname.lastname@example.org
After you set up your search criteria you can click on the "Create filter with this search" link at the bottom of the window.
Creating your Custom Filter
Now you can choose how you want your filter to behave. The options are quite strait forward.
Option to apply to matching conversations
Notice you can check a box that will allow you to apply this filter to all of the conversations in your Gmail that match the criteria that you have set. This can be a really powerful tool to be able to quickly organize your emails.
Now just click on the "Create filter" button and the new filter will be applied to you mail and all future mail that meets the filter you have created.