I have a strange problem. A company I work with sends out job offers to vendors (including myself) in the middle of the night, usually between 2 and 4 am, when I am asleep. By the time I wake up, someone else has already taken the job.

Normally at night, I set my (Android) phone to Do Not Disturb mode as I don't want all the incessant other notifications from mail, chats, apps, etc., that don't require urgent attention. 

What I want to do:
I want to get just one type of mail from one particular sender to get through Do Not Disturb mode, and nothing else, but Do Not Disturb mode only allows exceptions to be made for phone calls and texts, not particular apps including GMail or similar. 

My first thought would be to use my mail server to filter ONLY the mail I want to see to a different dedicated account, and to then send only this mail to a separate cheapy phone that only has a mail program installed, nothing more (no SIM card, no chat apps, no nothing), safe in the knowledge that if that cheapy phone wakes me up during the night, it is something I want to see, and nothing else.

I'm sure there is a more elegant solution to this than what I've outlined here. Does anyone have any other suggestions as to how other ways to solve my problem?