Limited to 160 characters before it converts to MMS which usually costs, depending on your network and sim plan situation whether that sends or not.
I would say your phone plan blocks sending MMS, fortunately if you'd regret paying for extended text.
Perhaps consider using a chat app, WhatsApp is popular or maybe an email.
I believe depending on your network plan you could opt to send MMS as it needs permission to bill you for it.
Good luck.