Email frozen

I cannot receive any emails, nor open any existing emails. Every time I open Evolution it says 'generating message list' and 'checking folder consistency', nothing comes up and no old emails show in the inbox. This then times out and I get "Error whilst generating message list" and 'disk l/o error' in an ornage box across the top. The checking folder then carries on, going up in increments, then times out again and the orange box says 'database disk image is malformed', and eventually the whole thing freezes and I can't navigate to any other page and have to reboot.
This all started a few days ago when I tried to empty the trash!
Can anyone help?
Thanks in advance, and please be aware I don't understand techno speak!