A friend told me that I shouldn't use capital letters in my emails. Why not?

You can use capital letters in your emails...just don't use ALL capitals. It's considered rude. It's like yelling at someone.

Look at it this way; if you want to emphasize something in a sentence, you might capitalize the word, right? (example: "I am NOT going to do that" or "I am not going to do THAT") So if you capitalize EVERYTHING, it's like you're trying to emphasize EVERY SINGLE WORD IN THE ENTIRE MESSAGE.

People will actually feel as though you are yelling at them.

I hate getting emails from people who fill their emails with stuff like "lol" and "imho" and all that kind of stuff. It's beyond me! Any suggestions?

Unfortunately, shorthand like lol and imho have become a standard part of internet conversations, and you're just going to have to get used to it.

In general, very little "important" content is shorthanded, so you can usually get the meaning of an email even if you miss some of the nuances.

Here are just a handful of internet slang phrases to help you get started. Note: this list was updated and alphabetized in 2016.

• afaik: as far as I know
• bff: best friends forever
• bfn: bye for now
• brb: be right back
• btw: by the way 
• fwiw: for what it's worth
• gr8: great
• imho: in my humble opinion 
• imo: in my opinion 
• irl: in real life
• jk: just kidding
• l8r: later
• lmao: laughing my --- off 
• lol: laugh out loud
• np: no problem
• oic: oh, I see
• otoh: on the other hand
• rofl: roll on floor laughing
• smh: smack my head
• tmi: too much information
• wtf: what the ---
• ymmv: your mileage may vary

In addition to these, you may have to put up with "leet speak", which is almost like a code, in which letters are replaced by numbers and symbols which look similar. For example, the letter A is replaced by the number 4, and the letter S is replaced by a dollar sign. If it doesn't get too extreme, you can interpret without too much difficulty: 1 h@+3 l337 $p34k = "I hate leet speak"