I honestly had to sign up for this. As nice as this theme looks I would never use it for a few reasons:
1) I don't care if you wish to release something commercially, but do NOT release it saying a payment is required but saying it is a donation. These are not donating, you are requiring a purchase and I will be reporting you to PayPal for abusing the donate features of their site. I couldn't even purchase this if I wanted to because PayPal donations require you have a PayPal account whereas PayPal purchases don't.
2) You're attitude is horrible. Probably one of the worst of any developer I've seen, and I am a member of XDA-Developers. Don't shit on your customers (who are paying customers), not users **THEY ARE CUSTOMERS **, with that crappy attitude. If you are going to charge for something, except people to request bug fixes. It's honestly in good faith of a developer to ensure their software is bug free and well maintained. Basically, grow up.
Those are my main two points. I just cannot believe how much support this theme is getting when the developer is completely disrespectful and rude.
I'm sure my comment will be deleted, or criticized, but oh well. I use Roundcube and know how to use it without needing forum access. So ban me if you wish, I just had to put this out.