It would be useful to include the following Bulk related information in the Creating issues and comments from email article:

1) What is the precedence between the Bulk settings from the Mail Handler setup and the Advanced mail loop detection.

As far as it seems, the bulk settings from the Mail Handler setup will take precedence over the mail loop ones. Loop detection is verified only for the messages that pass the bulk check. Mail loop detection is the last check, everything else must be ok first.

2) What is the correct syntax in the Whitelisted domains configuration.

As far as it seems, the values specified the Whitelisted domains must have no quotes and be separated by comma. Also, leading and trailing spaces are ignored.