Basically title.

How do I know if I am being blacklisted by someone else when I send a message?

Will I get a system message in response stating something like: 'unable to send message'? Or something to that effect?

I tried searching this through google or reddit, but kept getting the same generic 'how to blacklist people' and couldn't find an answer to this question. I am well aware that a person no longer sees messages from people who is blacklisted, but how does the blacklisted person know their message won't be read?

Thank you for any help.