I cannot speak for all schedulers. Depending on the MSP I am scheduling for, the number of emails may vary. I have scheduled for MSP's where I have received hundreds of emails a day. It would take hours just to sort through emails.
I, too, mystery shop and I get really upset when a scheduler does not respond to my emails. Recently, I had a mystery shop that stated right in the shop info...do not cancel your shop if you need to reschedule the shop or just need a different date. I emailed the scheduler several times with no response. I ended up canceling the shop as I did not know if the shop was acceptable on the date I wanted. It is just so frustrating to email people with no response.
I do try and answer all emails as a scheduler. I might miss one here and there if the email goes into my junk mail by accident. I do put my cell phone number on all emails, so I am reachable. And I do answer the phone if I hear it or can. I do not always have my cell phone in my hand or near me.
There have been several MSP's that I have scheduled for that the person has a phone number and it goes to a central phone and you will get voicemail. Please leave a message on the voicemail. The voicemail sends the scheduler an email within seconds of the call. Sometimes it is a written text and sometimes you get the voicemail sent in the email. The scheduler then can call the shopper back if needed or email the shopper. Please give your complete name and phone number when leaving messages.
Always put your complete name, first and last name along with the type of shop and location in your emails. Schedulers do have many different accounts in a lot of cities. It saves the scheduler a lot of time if they do not have to search the database to see who you are. It could be the difference of getting an email or phone call now or maybe waiting many hours when the scheduler has to do research to find out who you are of the shop you are asking about.