Dovecot - login_greeting new line character

I am using this login_greeting for IMAP(S) protocol:

protocol imap {
  login_greeting = "mail.domain.eu -------> \"WELCOME TO PORT 993!\""
}

I want to know if it's possible to add a new line character at the beginning of the string? This doesn't work:

protocol imap {
  login_greeting = "\nmail.domain.eu -------> \"WELCOME TO PORT 993!\""
}

And this reports an error because it looks like configuration parameters have to be in one line:

protocol imap {
  login_greeting = "
  mail.domain.eu -------> \"WELCOME TO PORT 993!\""
}

Any other idea?