Update MailBoxTampering.yaml

[crmhh]

Required items, please complete

Change(s):

• Deletion of the EntityMapping for "Initiatedby"

  Reason for Change(s):

• The column "Initiatedby" in the EntityMappings is not present because of the project in line 67. The ANR is not deployable in Sentinel. Since the column "AccountName" is also in the EntityMappings, "Initiatedby" is in my opinion not necessary.

  Version Updated:

• Yes

  Testing Completed:

• Yes

  Checked that the validations are passing and have addressed any issues that are present:

• Yes