I can receive Email on my Nexus 7 but I can't open the messages. What is going on?

[AC Question]

I can receive E mail on my Nexus 7 but I cant open the messages.

My main E mail account is with my service provider Plusnet. When I put "Plusnet" into Google after a few clicks I get to my E mail but only a listing of the titles. When I try to open these nothing happens. So,I know who has sent me a message but I cant look at it!