I never did, but always wanted to when I first started reading. Now that the letters pages are back I've considered it here and there, but never felt the real need to. In fact, I usually just skim them any more, whereas I used to read them regularly in the late 90s and early 00s when I started reading.
Yep, to the translated X-Men comic. Got printed, too. But like the kid up there, I hardly ever read 'em anymore. Maybe because those Dark Horse and Image dudes love pages and pages of letters, who are all too long for French boy to read. I'm not putting my time in that.
I'll scan the Buffy/Angel letters pages for the possible hints towards future storylines, and sometimes the Saga pages but that's about it. But he's right, Dark Horse and Image do 3 page long letters pages sometime and it's a bit much.
I read the letter pages on Image books. The Lazarus one is great and I have fond memories of the letter pages of Powers. I also like the backmatter stuff in the Brubaker books.
I once sent a letter when I was a teen to the French mag publishing the translated Spidey comics but it did not get published.