I've been using Thunderbird for more than 15 years without experiencing inbox corruption. Granted, the first years the volume of mail was low compared to now.

I've been using Thunderbird for more than 15 years without experiencing inbox corruption. Granted, the first years the volume of mail was low compared to now. About 5 years ago I tried other clients, including Evolution and Claws, and stayed with Thunderbird. Evolution's UI was significantly slower than Thunderbird's, Claws and the others were less functional. I'm really happy Thunderbird development was rekindled, because it was getting noticeably behind. I manage six emails, two calendars and three USENET accounts with it, all in the same application, fast, and using less RAM than it takes GMail to display one inbox.