are my texts going through? (green arrow vs. black check)

[rooney10]

long story short, i want to make sure my texts are being seen. i have a super old phone, and i'm trying to text someone (whom i believe also has verizon).. anyways, in the past when i texted them, there'd be the "black check" in my sent folder. i tried 2 more recently and they've been marked with the "green arrow" now. they havent been responded to so i want to be sure that the person got them... does it sound possible that the other person blocked me (there's the slimmest of chances of this being the case, but i just want to make sure)- i dont get any "message failed" notifications or anything so i don't know. 

on a related note, what exactly do the black check and green arrow mean? some people never get the black check (im assuming because they dont have verizon).  however, some people almost always get the black check, yet on a few instances when i text them, it will never change from the green arrow (i know they received my text since they reply though) - im hoping that's just the case with this person, but i have no idea how to be sure... any help appreciated!

[vzw_customer_support]

Hi, Rooney10-

I would be happy to look into this concern with you! Typically a black check occurs when you are sending to a Verizon customers as verification its been delivered. Because we cannot verify if its been delivered to other carriers, you see a green arrow indicating it has been sent. If it doesn't send, it will display a red 'X'. I recommend reaching out to this person by calling to see if they are getting those messages. Let me know if you have confirmed these are not being delivered and need further assistance.

Thanks,
AdamE_VZW
Follow us on Twitter @VZWSupport

[rooney10]

in some instances lately though, even when i send to verizon users, it still displays a green arrow.. what does this mean? why wouldn't it become a black check?  many times i still get a reply so they obviously get it, but im concerned if i dont get a reply