FLASHING MAIBLOX ICON

So, for the past few weeks, I keep getting a message at the top, despite not having any actual new mail. I remember this happening a long time ago as well, and I'm assuming it's the same error? I'd like to do something about this as it's kinda driving me crazy a bit lol. If that's not too much to ask. ^^;

Ah! I didn't even know that option was there in the Mailbox. Much obliged for that help.