Hi Nick,

I do not want to use ISP or GMAIL service for sending.
I'm sending from my own domain a message to a gmail adress.

The error comes from postfix who constanly try to contact port 25 in order to see if the target SMTP server support TLS.
I don't know why but because Google no longer responding on port 25 the sending process stop here what ever I configure on postfix this damn software still try to connect on port 25 !

After a new try I realize that this is a new FW rules that my IPS add to the internet box :
Block all traffic on port 25 & 445
What a brillant idea... :-/
So big loss of time !