GTA V: Can't Reply To Emails?

[brandengroch]

So I know some emails you can't reply to. But these specific emails I know you can. Like the one where Jimmy emails Trevor once you complete The Fame or Shame mission. I got the email, and when I open it, no plus sign shows up. A red arrow shows up beside the email on the left when your scrolling through all them. But when I click on the email, all I get is just the red arrow in the bottom right corner? I know it's not really a big deal I'm just curious? Does that big red arrow to the left of the email mean that I've already replied to it? Cause I don't really remember, and I thought if you reply, it will show your reply instead of the email? Just a little confused and wondering if anyone knows what this is all about here? Thanks