Writing private messages does not work that good:
1. I had one lengthy message not beeing send, but telling me like "your message has been send, but you probably double clicked".
User error in combination with a maybe crappy system
2. One can write a lengthy message, but after sending it, it tells "the user has blocked PMs". Jeeeeez, then dont let me type a private message in the first place!!!
So you would like the software to check if the recipient you selected has PM receiving enabled, and if not block you from typing the message. What if you have two members selected of which only one has the PM receiving blocked?
Since it is server/client based and the server only gets input when you press the send button, it is then that it can check on receiver being enabled.
What could be an option, and I don't know if this is already done, is that when a member has PM blocked it should not show the "Send PM" option in that persons profile, but then it would have to check if the one looking at the profile is in the ignore list of the selected member.
So to conclude, even though you might have a valid complaint, to solve it requires a lot of thinking and software modifications that no one wants to do.
Sometimes it is just better to not work yourself up over something that is not in reach of your control.
Another work around that can help, is to type the message in a text editor and copy paste it in the PM message window. This way you can save it and don't have to type it all over if needed.