Mail routing from first login letter

Hi, We use postfix as a frontal MTA . Frontal MTA mail are surname.n...@domain.fr , and store account are sn...@account.fr. For the moment we only have one mail account server and with aliases we route mail like this: surname.n...@domain.fr:sn...@account.fr) We want to create 2 server to store

weird problem

Hello, We upgrade our postfix with ssl/auth connection. postfix-2.3.3-2.3.el5_6 centos 5 32bits to postfix-2.6.6-2.2.el6_1.x86_64 centos 6 64bits Some user said that they must click 2 times on send email for their email to be sended. (first time say : could not contact server) .. but it work