Handy tip: If you want to appear sincere on the internet, use an exclamation point.

"Thanks for posting my article!" doesn't come off sarcastic, even if it overstates your exuberance.

I sort of hate to continue this thread, but that is definitely my rule for email. I decided a few years ago that, if it came down to it, I'd rather come across as an over-exuberant (can't think of a polite word for 'idiot') than come across as an asshole. Most of the time, at least.

The upside is that if you add an exclamation point, you can get away with much shorter messages!

A smiley works as well :)

THANKS FOR POSTING MY ARTICLE! :) <3

(But seriously, I was sincere in my appreciation and not being a dick. I think the above syntax tips are all great suggestions.)

No no no no. Take people seriously on the Internet, at face value, and eventually people will realize that sarcasm doesn't work and will stop using it.

Oh, gehar, you're always being so sarcastic! ;)