Why not getting Read receipt to messages sent to a particular contact

[AC Question]

When i send an SMS. 1st it shows the single tick. (That means it hs been sent). after sending the message when I click Details , it shows the sms sent date & time. and when i click Report, it shows as Status Pending...

But, later after hour's when I again click Report, Status shows as Unsuccessful & in front of Delivered : It shows as Date & time of when the message was sent.

and the Single Tick which was earlier of sent changes to Red colour Explanation mark (!).

 

[Tim1954]

Hm. You don't usually get read and delivery report on sms, only mms.
The read exclamation mark means not sent. Tap it and you should get the option to resend or a description of what the problem is.