Yes, I am serious, deadly serious.
I have also developed .NET application that people can download. And for sure, I won't force the users to go to .NET 4, because it too fresh to force them. Also, my code doesn't need the .NET 4 stack.
But things are even more, far more, critical for servers. Large amount of users use the website. Yaf is not the only thing running on the server. I have a dedicated server running in a data center. Upgrading the server involves huge amount of time and risks. Yes, at home on my PC, I just upgrade. But a remote server is something else.
Note that I need to go to IIS7+ in order to use .NET 4. This is not standard on W2K3. Meaning I have to upgrade all sites etc.
For sure, I need to move to another server in a year maybe. Then I can install everything on the new server preparing it in the background and I can move within minutes/hours. But for now, I cannot take the risk of crashing the system.
I did revert to the version in the repository to just before the .NET4 conversion. I will try to go from there, to see if I can fix the email problem.
Too bad, I liked to follow YAF and be up to date. But the developers have made their choise.