What can I do if a character keeps spamming or insulting me?
If a character is spamming or insulting you, you can simply ignore messages of this character. To do so, add the character to your "Ignore List" in the info menu under communication. You can either "Add" single characters from which you do not want to receive messages, or you can select "All but friends". If you select the latter option, only characters that you have added as "Friends" will be able to contact you.
To receive messages from ignored characters again, simply "Remove" them from your ignore list. By selecting "Ignore off", you will receive messages from all characters again, and all ignored characters are removed from the ignore list.