[注：下文是群邮件的内容，标题是新拟的 (略修订)，原标题略。]

This is coming to you from Yiwei LI (PhD, Applied math), Taiyuan University of Science and Technology  (TYUST) Taiyuan, China

Scratch time is a topic under the column of Theory of Mathematics (TOM), an attempted framework to understand invented and un-invented mathematics from the core.

The spirit of popular science can be summarized as "Not you; not you; not you ..." ---- Dr. Notya.

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Actually, I planed to state the spirit of analysis is to divide things to avoid wastes.

---- In some earlier stage (around 2013), I divided the mailing list into a few groups.

---- Say, Monday group, Tuesday group, ..., Sunday group.

---- To measure the rate of viewing, I included a link to any old blog article of mine.

---- Each blog article is associated with a viewing counter.

---- To avoid confusion among the hits, I arranged sufficient time intervals among the groups.

---- In this way, I could count the hits from each group.

---- I do not remember the specific situation, but the general rate of viewing is of ~ 50%.

---- The situation was then informed to the recipients by including a link of a new blog article carrying this information.

---- That would have brought me a chance of verification or calibration.

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At that time, a unique question arose in my mind —— How to know who viewed the old blog article exactly?

---- The rate of viewing can be measured due to a key condition: individuals feel safe in a group.

---- Another condition is the sufficient time intervals.

---- So, for one thing, the matter must be conducted on the level of groups; for another, I feel curious to know who contributed to the hits.

---- It seems an impossible task.

---- But, the question has stayed in my mind since then.

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The situation was changed by an accident.

---- At some point, I started considering if there was any forbidden zone in my mindset.

---- So, I tentatively reached to a university in the legend.

---- By the first trial, I earned a rejection (corrected later*).

---- I tried several addresses.

---- Before that, I indeed experienced mail rejections, occasionally.

---- It was never inspiring.

---- But very curiously, this time I suddenly realized the way to find out the answer of the question above ——

---- Assume that you've setup a depository of rejection addresses, denoted as {x, x, x, ...}.

---- Assume that you wish to know if a specific recipient, denoted as s, views your flock emails.

---- Then, you can organize a mailing list like {x x x x x x s x x x} —— no wastes.

---- After that, you can freely do your tests ——

---- For one thing, s feels safe in a "group"; for another, any x would not contribute confusions to the hits with a certainty of mathematics.

---- Credits go to PU for the accidental inspiration ^_6.

* I prefer to avoid a long story.

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Note: I just consider the matter theoretically, to show the rate of veiwing from a mailing list can be possibly analyzed on the level of "atom".

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Comment: Do not reject emails for one's own sake —— one more source of information, one more chance of knowing.