Bulk email to a selection of candidates

I understand that when a user wants to send a bulk email to a selection of the candidates then you need to click on the little box to the left of their name. However, if I click onto the next screen of candidates the boxes that I ticked on the first page are no longer ticked. For example, I have 50 candidates and I want to email 2 of them. I find and put a tick in the box of the first candidate. The second candidate is on the next page. By clicking onto the next page the first candidate is now no longer ticked. Is this how it is supposed to work?

Thanks in advance :)
Rebecca