Script Summary: Updated 6/26/07 Now works for cc & bcc Automatically Select to send from different from addresses based on the addresses you are sending to. For example when sending to a .edu address you can have gmail use your school address as the from address.
I use my Gmail account for all email, and have my school email forwarded to Gmail. Gmail allows me to change the from address so It looks like I sent it from my school account but I always forget to do it.
When the send button is clicked this script checks all addresses in the "To" field and if any of them match a certain criteria then it changes the from address that Gmail uses.
To use it you must install the script and modify it to suit your preferences. There are two things that need to be modified, which from address to use and the regular expression of when to use this address. The default is to use the second from address (index=1) when sending to any .edu email addresses. These parameters can easily be changed by modifying two variables at the top of the script.
Hope someone else finds this useful.