On twitter, how come when I try to send direct messages,they are forbidden?

[Averil]

Like if I send a direct message to someone, it says "DM cannot be posted: (forbidden) does that person have to follow you? The only people that work are @support and @ twitter.
* why are they "forbidden"?
* what can help?

[Slamet]

Hi!

Of course , the people that you want to DM for is need to follow you , and if the people follow you and you not following back , it's mean only you can send a direct message for him but they can't reply because you not following him back.
yes some user available to send DM without followed you example mozilla firefox on twitter.

Hope it's help .

Thanks