If your email program is set to attach the full text of the original post to your reply, change the setting. Do not resend the entire original message. If you don't know how to change your settings, please ask for help on the list. If you repeatedly post entire messages, we're going to discuss this with you. Try to keep signature files down to a few lines.
Freelance is an ad-free list, but long sigs are still a blight on humanity.
If you are filtering your email, you can use this as a variable. If you're on digest mode, be sure to change the subject heading when you reply to a post. Always check this before you send your reply. You do the work, so you are the best judge of whether something is on-topic. Send them privately to the person you're thanking.