Hi, I had my website unmaintained for a period and I had a huge spam attack at that time (around 3 month back). But since then it is very well maintained and I don't have any spam for a long time. But still in my google webmaster, I see thousands of 404 errors coming everyday. And those links are coming from different spam sites. So, my question is whether it is okay (in terms of google ranking or other) and I should forget it. Or should I do something (no idea what)? Any advice will be highly appreciated.