Filtering conversations matching a subject but not from a specific email

Question

I use GMail for my Kijiji postings. (For those unaware, it's a lot like Craigslist, except it's popular in Canada!)

I have a filter set up with:

Matches: from:([email protected]) subject:(Reply to your Ad on Kijiji)
Do this: Apply label "Kijiji Reply"

See, when someone replies to my ad that I have posted, I get a message from [email protected] with a subject of, for example, Reply to your "Oak Coffee Table" Ad on Kijiji.

This is working just fine. The problem is that I also use my Kijiji to respond to other people's ads. What I would like to do is create a label called "Kijiji Inquiry" that I can use to track those conversations. I'm running into one actual problem, and I foresee another problem soon after that.

1. I can't seem to filter messages of the pattern Matches: NOT from:([email protected]) subject:(Reply to your Ad on Kijiji)
2. If I do find a way to match it, I don't want my existing Kijiji Reply conversations to get marked as Kijiji Inquiry, since when I get that message from [email protected], I will respond to the reply-to. When they reply back it should match the subject pattern, but since it's me selling something, I don't want it also to get marked into my buying-stuff bucket.

Can I get around these problems? Is there an addon I can get to handle this?

Edit: This question seems to indicate you can filter out by email, but doesn't say how he does it, nor that it works like he wants. The answer there doesn't seem appropriate to this question either.

Answer 1

If you use the minus sign, it will work.

Instead of " Matches: NOT from:([email protected])", just use

 Matches: -from:([email protected])

I tried this in a search and worked just fine, so, it will probably work in the filter too.