First, a little preparation goes a long way in principle. And so, reading is no different. Then, an alert in the message preview line gets us ready for important information. Hence, we may look over an entire document. It follows, long message alert in subject line for email prepares to read. Given, proper netiquette to tell the recipient in the topic that it is not a short read. As a result, do put an alert in the sentence that appears in the inbox.
Long Message Netiquette For Email



Next, long email are not usually read. However, we may be able to give good reason to do it. And so, content resonates more with more words.
Then, write long in the message subject if a message is more than three paragraphs. This mentally prepares the recipient to read an email now or save it for later.
Text Length
Honesty goes a long way on the internet. If the recipient of an email knows that it is long from the subject line they may read it. As opposed to deleting it immediately when they open it and see its length.
Long Message Netiquette
Tell the recipient if the email is long. Hence, do it in the subject. Otherwise, it may get deleted.