Perhaps you could just set aside a time at the end of the day or the end of week to check your e-mails when you would not feel so overwhelmed and simply ignore the e-mails the rest of the time irregardless of when the e-mails are sent. Also you might mention in your logs that you want a delayed "Thanks" suggesting the day and time or state that you want no "Thanks" at all. I do not know about anybody else but it never occurred to me that thanking a Waymarker or Geocacher would be a problem!! Has it been a problem for anyone else??