The ONLY reason I use your competitor (Google Gmail) more than Live mail is that Gmail is the only program that allows me to send email to my 250 students (I teach at a large university). I know your small sender limit is probably a precaution against spam, but those people find ways around it, and the rest of us are all treated as potential spammers. Aaaargh.
I would use Windows only services if they didn't have silly limits like this one. I mean, how else am I going to do my work if I have more than 25 senders (or whatever your limit is).
Can you lift the ceiling?!