I've done this a number of times, I don't send out tons of emails usually 3 or 4 max. and I'm always willing and wanting to see every lady I send an email to. All the laidies have been thoroughly researched by me before an email gets sent.  I keep the email exchanges brief, as soon as I get a feel for the lady I want to see I book the appointment with her. Many times it's the first lady that replies.  Remember, I only send emails to ladies I really want to see. And then I notify the other ladies I won't be able to see them this trip, but might see them on a future trip.   I also book the day and time in advance, usually  before I take the trip. When I get the response "call me when you get to town" I normally decline to proceed. Most well reviewed quality TER escorts don't mind booking a week in advance. Now remember this is a guys opinion, not an escorts opinion.  Good luck!

you consider these emails to be some kind of auditions. If a lady chooses not to engage in more than a fairly brief and to-the-point reply, I wouldn't take that as a bad sign.

Personally, I don't find email a very reliable way to tell what an escort will be like in person. Reviews, etc., are a far better indicator. Besides, many escorts have an assistant who handles all their email.

It seems what you're doing is not actually looking to book, but looking to be prescreened, get a feel for her personality and to check her availability.  I see nothing wrong with an intro note (with all the pertinent screening info) stating all of the above.  Mention you are not sure of your own schedule but X day and X time is likely when you'll be available.  It is then the lady's choice whether or not she completes the screening process (if you don't book, YOU are not the one wasting her time, SHE is).  She can easily reply that your anticipated day/time either works or doesn't, what else she may need for screening (or other details pertinent to HER) or whatever.

I would imagine most ladies would be understanding this process, so long as you're transparent about your motives.  Honesty is far better than double booking or canceling/NCNS.  I think "time wasting" is generally more about actually setting an appointment and then canceling, or her having to drag your screening info out of you as if it were a tooth extraction, or pointless, vague emails wanting to "just chat" without any move toward finalizing an appointment.

Be honest, volunteer whatever info is necessary for her to feel comfortable and give plenty of notice (the more the better) if you choose not to pursue an appointment with her and you should be fine.

I often contact a provider or 2 in advance, ussually by email with the headding "advance screening".  I am up front about when the opportunity will happen & give the lady enough time to screen me...  and to make sure our schedules mesh.
 
It has always been well recieved, though there are those who (I've heard) reply to contact the day of the desired appointment.  Obiviously there's inadequate time for proper screening at that point...  and my take is these are 'phone only' girls.  My problem with the short notice system is that some do not make firm appointments & stick to them.    These fast service type business plan...  they often tell every body to show up hoping that some will actually do so.  The first one to arrive gets the girl, who shuts her phone off or does not answer until she's available again.   If one is driving a distance...  and can't just hang around endlessly...  this is unacceptable to me.

I do not see anything wrong with wanting to be pre-screened and providing the required info.If you contact a couple of providers I do not see anything wrong with this as you have not committed to anything you are just inquiring on availability and if she will be in town on the dates of your trip.I have encountered this with many gentlemen that are interested in me but do not have their travel dates firmed up they send an email introducing themselves and maybe an idea of when they will be here and their references.Check things out and when they have their dates firmed up and want to set an appointment I have already screened them so there is no issue.There have been a few occasions where the gentleman did not end up coming or had to reschedule I have no problem with this but the majority of the times the gents book and we have a fabulous time.

Time waster to me is someone who has no intention of coming to my town but wants to go back and forth with multiple emails just to get a name and references from him.Or inquiring on rates when they are clearly posted on my website I direct these guys to my website for the info I will need and still get multiple emails without the pertinent info provided.One last timewaster is the one that contacts many providers at the same time does not provide info and when asked for info says that is okay some other lady is willing to see him without this info.She has already responded and he has set an appt already all in the span in the 10min it took me to get the email and respond back.So,as long as you are not doing any of the things I mentioned above you are not a timewaster IMO.