Is Folder capacity limited?

I am testing eM-Client to replace Win. Live Mail and ran into a capacity problem after loading less than 1% of my e-mails from Win. Live Mail. I read that eM-Client handles large volumes of e-mail, but with only 3,000 e-mails imported, I get the error message: [IMAP]NO [OVERQUOTA] Mailbox is full /Blocks limit exceeded / Inode … for over 250 e-mails

Is eM-Client designed for the casual user or for running businesses?
Do I need to find a replacement desktop client to handle 1 million e-mails & 10,000 contacts?
If I have to change, I hope I can transfer those few e-mails I already loaded !

eM Client has no limit, but your server does, and that is where this error is coming from.

Rather than upload this imported data to the server, why not store it on your computer in eM Client’s Local Folders?

If Local Folders are not visible, you can enable them by selecting Menu> Settings > General > Show Local Folders.