Whatsapp business won't block a number?

Question

whatsapp

Hello!
Does anyone use whatsapp business?
Applications with a left phone number come to the email, I want a message to be automatically sent to the client in WhatsApp, if he has one (if there is no WhatsApp, it is necessary that it be noted that the message has not been sent)
"Hello! You left us an application for the manufacture of products, etc. ,"
about the essence of the message will be the same for everyone
. There is a question: Watsap will not block the number for this?
Someone wrote on the forum after they sent 200 identical outgoing messages, the number was blocked, or does it only work with incoming messages in whatsapp, and if it is the first to send out, it takes it for spam, is that so, is there anyone who used this function?

Answer 1

antispam is constantly changing,
you can send 200 not a second

Answer 2

case in unicode, use like this:
preg_match("/^[a-z0-9а-я]+$/iu",$login);

Answer 3

Add the /u modifier