Форумы / Cotonti / Support / Blank registration emails?

You might need to check "Email title" option in admin.php?m=config&n=edit&o=core&p=title. Normally it looks something like this:

{MAIL_BODY}

{SITE_TITLE} - {SITE_URL}
{SITE_DESCRIPTION}

While yours might be blank judging by blank emails.