Postfix can't send mails externally



I installed with problems sending email externally already tried several posts related to this and I am not able to make it work… on my mail queue mails get pending and gets timout

D80E8C196E     5358 Fri Aug 11 09:59:24  sender
(connect to[]:25: Connection timed out)

I had checked by changing the smtp port … But after changing there was no mail on the queue and no mail sended to the destination.

please help me



Did you see this guide:-