The author of Indistractable, Nir Eyal, provides a helpful autoresponder script for your mobile phone to minimize distraction during your deep work. He suggests:
Hi! This is an automated reply to let you know I’m indistractable at the moment. I will not see your message right away but I’ll get back to you shortly. (I’m not receiving notifications. If this is urgent, reply “urgent” to send a notification through with your original message.)
You can also replace the words “I’m indistractable at the moment” with “I’m on a deadline”. Activate automated replies in iOS by going to Settings>Do Not Disturb. You’ll have the ability to customize several factors: pre-scheduling your autoresponse, unsilencing a second call from the same person within three minutes, allowing only select contacts to message/call, and more. For similar functionality on Android, check out Auto Message.
Source: Ben Meer