I always keep my email online. I do look into it whenever I get a desktop notification of a New Email or a New reply email to one of my emails.
I'm constantly tied to my email all day. I only check it when I get a notification, which is like every 5 - 20 minutes.
I have Thunderbird at startup so whenever im on my pc i get instant email notifications, if im not by my pc i check from time to time via phone but only if i wait some really important email.
I have signed into my mobile so I get notification right away when I get any mail on my mobile so I check often like in every few mins.