I use Thunderbird for my email. This generally handles attachments fine, knowing which application to use to open them.
Someone sent me a .php file today. Being a .NET developer, and not a great fan of PHP (ducks to avoid fling bricks from any passing PHP fans), I don’t have a default application for opening .php files.
No problem, Thunderbird is intelligent enough to ask me what it should use…
Erm, well maybe it’s not that intelligent after all!
In fairness, I’m not sure where it picks up the suggestions, so it may be that Windows is to blame. Maybe not. Either way, at least two out of those three were pretty dumb!