Dear Valued Customer / Revered Business Leader / Esteemed Colleague / Grateful Report
I am afraid that I am out of office until January 4th with limited access to email. If your message is urgent, please email me with the words “Business is happening!” in the subject line, and I will endeavour to get back to you (those words allow me to transcend the requirement for WiFi). Alternatively, activate the Bat Signal (Batman and I were at business school together) or notify the Executive Coach elders, and assistance should be with you shortly.
Yours sincerely / faithfully / graciously (depending on level of acquaintance and seniority)