As you can see from this old archive of starwars .com, the first teaser released in November 1998: https://web.archive.org/web/20061224050901oe_/http://www.starwars.com/episode-i/release/trailer/archive.html
And here’s the direct .mov link to it (you can download and watch with vlc): https://web.archive.org/web/20061225164218oe_/http://www.starwars.com/episode-i/release/trailer/mov/menace00.mov
It looks the same as the teasers uploaded to youtube.