I currently use a BlackBerry 6 device using BIS for POP mail. At home, I use Outlook connected to Shaw's POP servers.
This configuration suits my needs perfectly. I can delete messages from my phone and have Outlook download them for saving when I get home. Not every message I receive needs to be handled on my phone and some are of a confidential nature. Since my phone does occasionally get used by friends, being able to delete messages from the phone while leaving them on the server is an important feature.
My understanding is that Shaw doesn't allow connections to the SMTP server from outside their network, so that would make sending emails from the BB10 phone impossible, unless using the Webmail/EAS system. The downfall with EAS is that messages are always sync'd, meaning I cannot delete emails from the phone and leave them on the server, nor can I download messages at home and leave a select few on my phone.
I must be missing something - There's got to be a way to send/receive messages from my phone while being able to delete them from the phone but not the mailbox.