Agree with bluejay but would go even further. 'Foreword' and 'preface' are definitely only for books, and 'editorial' is for the opinion of the editor(s). To my ears, anything along the lines of 'introduction' is better suited to a speech or a one-time publication, not something published regularly like a newsletter.
If you have to give the piece the same title every issue (every month, every quarter, whatever), I would refer to it behind the scenes (but not in print) as the boss's column, and simply call it something like 'From the CEO,' 'From Our Management,' 'A Word from the Managing Director,' etc.
An even better choice in my opinion (though one that may not occur to bosses unless you suggest it to them) would be to give it a main headline that reflects its actual content, so that people will have more incentive to read it. For example, 'October Focus on Safety' or 'Staff Invited to Holiday Party,' with the column title like 'From Our CEO' only as a subhead in smaller print above, either right- or left-aligned. This can work quite well combined with the writer's picture and (scanned) signature at the end of the column for an extra personal touch.