A) It should be a MINIMUM of four to five paragraphs in length.
Normally, not much that's important takes one or two paragraphs. Unless something is going on and you really don't have time to do more, or something in how the plot is set up keeps you from doing any more until another post comes out, or you get a reply from someone else, you really should be shooting for at least four paragraphs.

This really isn't all that difficult a goal and I'm sure you're all capable of it. Paragraphs generally run 3-7 sentences, so you're looking at a minimum of 12 sentences in a post. Generally you will find yourself doing more than that probably.

B) There must be some sort of dialogue.
Though this says must I would actually tend to say there are exceptions here also. If you're writing a post with your character alone in their room say... getting ready for an away mission, it's possible that you won't have them say anything. You won't have a lot of posts like this though. While showing how they prepare for a possibly dangerous situation can be good for fleshing out your character a bit, if you make a habit of it you'll be risking causing boredom.

C) There must be description.
I really don't see that anyone would be likely to write a post that contained no description at all. You should probably go a bit beyond bare minimum on this. If you're in an alien environment what most sticks out to your character about this place? What one person notices might be different from another. One person in a bar may be caught up looking at a particularly attractive waitress while another is more interested in the way the piano player sways as he goes through a particularly catchy song.

D) It should be in PAST tense.
This one I believe is very important also. For an example of a present tense piece:

She walks down the corridor and turns to face the door. Pressing the panel she waits impatiently and as the door opens she smiles in amusement to find the cat staring at her as if to say, "You're late."

And now in past tense.

She walked down the corridor and turned to face the door. After pressing the panel she waited impatiently for the door to open and found herself smiling in amusement to find the cat staring at her as if to say, "You're late."

Those two say basically the same thing of course but I found the second version easier to write and in general I find past tense easier to read. For most purposes the style used in writing posts is that of a novel. This is partly because it's a style that nearly everyone is familiar and comfortable with.

I'm not even going to try to rewrite that in future tense since I doubt anyone would ever try that. I'm also not going to say that you can't use present tense. However, if you choose to use present you need to make sure that you don't slip back and forth between that and past (as I very nearly did several times in only that few sentences). Really, your life and the life of your readers will probably be easiest if you stick with past tense on all posts.

E) Must have a proper heading.
One thing that your post is going to have is a title. Try not to make this too long, and it would probably be best if it were at least somewhat connected to what happens. (Sure catchy titles are good, but don't make them so clever that when you skim through your e-mail you can't find the post you're thinking of because you don't remember the fancy title!)

The title will almost always go in the Subject area of your message. Another thing that might go up there depending on what sim you have is the name of the game or ship that you're in. The program that forwards e-mail for our class automatically puts Class 9: at the beginning of the subject of every message it processes. Some services aren't set up that way and if that were the case you would simply have to type that extra bit in for yourself.

The reason that -- one way or another -- something like that is almost always used is that some people belong to multiple games and need a quick way to sort through the mail (there are also some e-mail programs that can be told to move all e-mail with subject's containing a particular word or set of words). There are also people who receive a lot of spam (advertisement e-mail) and having the game name in the subject makes it clear that it's legitimate e-mail so that they won't accidentally delete your message.

For some, but not all, games you'll also be putting the last name of the main characters of the post at the end of the title. This makes it easier if someone is trying to find something out about a particular character and it helps the reader get it immediately straight in their mind who is involved with the post.

If all three of these are used then a sample subject may look something like: Enterprise: Reporting for Duty (Johnson, Kilmer)

The headers within a message will also vary. I was in one sim that required all of the posts to label both what day and what time of day the post occurred on at the beginning of the message. This one probably varies to much for me to give you a good generalization beyond that most people begin the body of their posts by restating the title and listing the authors (either by real name or their character name). You may also list things like what NPCs were used, or the location that the post takes place at, or any OOC (Out of Character) comments that you'd like to make to the other players before beginning the post itself.

F) No indentions.
This just means don't indent your paragraphs. While this isn't standard for general writing I've found that it tends to be easier for my eyes to pick up the breaks between paragraphs if it's a full space instead of a five space indentation.

G) Paragraphs must be broken by a single space.
See letter F.

E) Spelling Errors
Do your best to keep these to a minimum. If your e-mail program doesn't have a spell checking program (though many do) there are free e-mail accounts that you can sign up for that do. Or you can just try to be really careful.

Along with this one comes grammar mistakes. While you don't have to be aware of every tiny bit of the English language try not to make basic mistakes out of carelessness. It's often just easier to read when there aren't distracting errors popping out at you.

And it's not on the list but you should try to write all or nearly all messages in third person. Third person is when you're referring to your character as "he" or "she" instead of saying "I" or "me".  Occasionally a post might be done in first person but it's a bad habit to get into. One of the worst mistakes I've ever seen made in a post was someone (and I think they were actually even a GM at the time though I don't know if they still are) didn't even think to not use first person when writing a joint post with someone. So paragraph one might have been first person, and paragraph two was third person and paragraph three was first person and so on.

Class information given by Cossie 16 Feb 99, Original Points written by Jordan; edited by Chirstyn 2001 & 2002