Thank you for your follow-up. Please allow me to respond to each point you brought up directly:
My husband sent me a divorce petition in the mail, it had no legal stamp on it but it was on his attornry's stationary, is this how it is done?
That is permitted so long as the document was filed. The letterhead shows that this was a valid petition, and while you can arguably contest service (if it was never filed), this is a non-issue if you received the documentation and responded to it.
second, we have been married 20 years, separated for 3. we have a pension fund in both our names, he is refusing to give me half instead he is giving me alimony of 500.0, shouldn't i get half the pension seein my name is XXXXX XXXXX?
That depends on a few factors. Florida is not a 'community property' state where all assets are split 50/50. The courts instead employ 'equitable distribution', which evaluates what would be a fair split of the assets but not necessarily an equal one. I do agree with you that if this amount was started while you were both married, you both have your name on the account, you both contributed to the account, then you do have a valid claim for a very high portion (or half). If he is refusing to budge, explain to him that as you have been married a long time, you could seek a higher amount for alimony which would affect his portion of the estate.