timed out while receiving the initial server greeting

I'm trying to host a postfix mail server.I have a box with a fixed IP and also a mx record and spf record that link my box IP to my dns record. I can telnet to alt4.gmail-smtp-in.l.google.com 25 but when I send a mail to me@gmail.com, I still receive this error **mailq**

-Queue ID-  --Size-- ----Arrival Time---- -Sender/Recipient-------
CB502D9735*     389 Tue Jul 18 01:28:17  root@mydomain.com
                                         me@gmail.com

37A54D8C06      389 Tue Jul 18 00:26:34  root@mydomain.com
(conversation with alt4.gmail-smtp-in.l.google.com[74.125.200.26] timed out while receiving the initial server greeting)
                                         me@gmail.com


BBC43D9557      389 Tue Jul 18 01:11:20  root@mydomain.com
(conversation with alt4.gmail-smtp-in.l.google.com[74.125.200.26] timed out while receiving the initial server greeting)
                                         me@gmail.com

telnet alt4.gmail-smtp-in.l.google.com 25


Trying 74.125.200.27...
Connected to alt4.gmail-smtp-in.l.google.com.
Escape character is '^]'.