How can I get around calling him?

I work w/a group on various projects. I am the team lead and send 2-3 general emails/wk to the group. One guy keeps saying that I need to call him instead b/c email and text are impersonal. It's not that he doesn't ck his email b/c he is obsessed w/his PDA and carries it w/him everywhere he goes. When, I call, he talks about other stuff than what I called for. My husband does not like this AT ALL. I just need to send general info or have a general question - so email and text work best. He won't respond unless I call him. What is his deal, and how can I get around this?