PostFix don't work

Hello,
I have a cloud server on Google Cloud Platform.

Clean installation of Ubuntu 18.04. The entire firewall is off, it doesn’t block any traffic.

The problem is that from my gmail account I can send emails to the domain inbox, but I can’t send from the domain inbox to my GMAIL account.

Errors:
May 05 02:36:28 host postfix/postfix-script[9275]: starting the Postfix mail system
May 05 02:36:28 host postfix/master[9277]: daemon started – version 3.3.0, configuration /etc/postfix
May 05 02:36:28 host postfix/qmgr[9279]: A4F66FDE16: from=admin@icekillers.pl, size=848, nrcpt=1 (queue active)
May 05 02:36:59 host postfix/smtp[9301]: connect to gmail-smtp-in.l.google.com[173.194.76.26]:25: Connection timed out
May 05 02:36:59 host postfix/smtp[9301]: connect to gmail-smtp-in.l.google.com[2a00:1450:400c:c00::1a]:25: Network is unreachable
May 05 02:36:59 host postfix/smtp[9301]: connect to alt1.gmail-smtp-in.l.google.com[2a00:1450:4010:c03::1a]:25: Network is unreachable
May 05 02:37:29 host postfix/smtp[9301]: connect to alt1.gmail-smtp-in.l.google.com[209.85.233.26]:25: Connection timed out
May 05 02:37:59 host postfix/smtp[9301]: connect to alt2.gmail-smtp-in.l.google.com[142.250.4.26]:25: Connection timed out
May 05 02:37:59 host postfix/smtp[9301]: A4F66FDE16: to=xtheszymekx@gmail.com, relay=none, delay=665, delays=575/0.03/90/0, dsn=4.4.1, status=deferred (connect to alt2.gmail-smtp-in.l.google.com[142.250.4.26]:25: Connection timed out)
May 05 02:41:28 host postfix/qmgr[9279]: 53687FDE17: from=admin@icekillers.pl, size=848, nrcpt=1 (queue active)
May 05 02:41:28 host postfix/qmgr[9279]: AC7E8FDE15: from=admin@icekillers.pl, size=865, nrcpt=1 (queue active)
May 05 02:41:28 host postfix/qmgr[9279]: 346B1FDE12: from=admin@icekillers.pl, size=1172, nrcpt=1 (queue active)
May 05 02:41:28 host postfix/smtp[9428]: connect to gmail-smtp-in.l.google.com[2a00:1450:400c:c00::1b]:25: Network is unreachable
May 05 02:41:58 host postfix/smtp[9426]: connect to gmail-smtp-in.l.google.com[173.194.76.26]:25: Connection timed out
May 05 02:41:58 host postfix/smtp[9427]: connect to gmail-smtp-in.l.google.com[173.194.76.26]:25: Connection timed out
May 05 02:41:58 host postfix/smtp[9426]: connect to gmail-smtp-in.l.google.com[2a00:1450:400c:c00::1b]:25: Network is unreachable
May 05 02:41:58 host postfix/smtp[9427]: connect to gmail-smtp-in.l.google.com[2a00:1450:400c:c00::1a]:25: Network is unreachable
May 05 02:41:58 host postfix/smtp[9426]: connect to alt1.gmail-smtp-in.l.google.com[2a00:1450:4010:c03::1b]:25: Network is unreachable
May 05 02:41:58 host postfix/smtp[9428]: connect to gmail-smtp-in.l.google.com[173.194.76.26]:25: Connection timed out
May 05 02:41:58 host postfix/smtp[9428]: connect to alt1.gmail-smtp-in.l.google.com[2a00:1450:4010:c03::1b]:25: Network is unreachable
May 05 02:42:28 host postfix/smtp[9426]: connect to alt1.gmail-smtp-in.l.google.com[209.85.233.26]:25: Connection timed out
May 05 02:42:28 host postfix/smtp[9427]: connect to alt1.gmail-smtp-in.l.google.com[209.85.233.26]:25: Connection timed out
May 05 02:42:28 host postfix/smtp[9427]: connect to alt1.gmail-smtp-in.l.google.com[2a00:1450:4010:c03::1b]:25: Network is unreachable
May 05 02:42:28 host postfix/smtp[9428]: connect to alt1.gmail-smtp-in.l.google.com[209.85.233.26]:25: Connection timed out
May 05 02:42:28 host postfix/smtp[9428]: connect to alt2.gmail-smtp-in.l.google.com[2404:6800:4003:c06::1b]:25: Network is unreachable
May 05 02:42:28 host postfix/smtp[9428]: 346B1FDE12: to=xtheszymekx@gmail.com, relay=none, delay=1263, delays=1203/0.02/60/0, dsn=4.4.1, status=deferred (connect to alt2.gmail-smtp-in.l.google.com[2404:6800:4003:c06::1b]:25: Network is unreachable)

Similar issues here, Postfix has some misconfiguration. Cant send mail from fresh install of CyberPanel. Some ideas anyone ?

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