Similar closed bug: Translation for system message not being used
In this case the system generated
with the standard message portion in Portuguese which is the native language of the OP.
System message in Portuguese
Este novo utilizador tentou criar múltiplas publicações com ligações ao mesmo domínio
Translated message in English
This new user attempted to create multiple publications with links to the same domain
The system message should be in the language of the admin reading the message which in my case would be English.