Little envelope with a blue arrow??

[cobaltnickel]

When I text one person, I get a little envelope with a blue arrow in the corner.

What does this mean?

 

[Droid Firefighter]

The message has been sent.

This post is Incredible 2!

 

[cobaltnickel]

But usually when the message sends it's either a green arrow or nothing at all :/
I've been having issues texting this specific person, and for the past week it's been "text message not sent" but now all of a sudden it's a blue arrow.

 

[Droid Firefighter]

Then I'm not sure. Sorry, hope you get it figured out. Try calling your carrier, they should know.

This post is Incredible 2!