What do I write or not write so that my emails are not trashed as spam?

We have a number of email contacts that we write from time to time. I
am afraid of writing something in the Subject or the text that a Spam
filter would trash it.

What do I write or not write so that my emails are not trashed as spam?
Thanks.
John Pendleton

Anything related to sales, sex, drugs, or mortgage.

Hi,

What yiferic said is true, but it really depends on the email service
in question. One of my friends uses hotmail hosted by MSN, and it
marks all email as spam that doesn't come from people in the address
book. Other clients can totally block any email that is not on a "safe
list" of names that the user trusts. It would help to  know which
services your email contacts are using. Generally, though, make your
subjects more personalinzed, maybe even include a few phrases relevant
to the topic of your message, even if they don't seem necessary.

-Hope it helps!

Me thinks a spammer would pay 200 dollars for this information.