While having filters to simplify the filing process of incoming messages is convenient, one of the aspects of setting rules in Outlook that seems to be missing in Gmail is the ability to set rules for outgoing messages as well.
For example, if I always want to mark a message for a "Read Receipt", I would prefer to have a rule that does it, than have to click the box on every message.
Also, if I need to CC or BCC someone on each outgoing message meeting a certain criteria, I should be able to set a rule for that as well (like you can in Outlook).
Filters are great, but they don't suit the purposes I need for outgoing messages, only for incoming ones.
For as long as Gmail has been around, I can't be the first person to have brought this up, or can I?
Best Answer
Gmail filters apply to sent mail by default. They do, however, not apply to drafts.
So, Jacob's answer describes the default process for making filters and it will indeed also work for mails sent by yourself.