I'm at work and told friend I cannot respond to emails until I finish work, got notifications on phone that she's sent me several emails -after I told her that I can't respond to emails until I have finished work

I can get onto emails on my phone, but if I respond to her email messages while I'm working, she will just send more than she does if I don't respond until I can after work

Is it unreasonable that I don't respond at all to her while I'm working?