why i won't be using gmail as much as I thought (at least for now)

i love the archive and labeling functions of gmail. but i don't intend to give up and stop using my shieldsplace.org and faithmaps.org email addresses. gmail was to replace my yahoo addr, which I use to check all my personal email addresses when i'm away from home without my laptop. but, apparently, google won't do that 'cause , according to motley fool, they can't search your other email addresses! now, i'm genuinely hoping this will change so haven't totally give up hope. i did send a note to google asking for this feature.