I receive E-mails, but I cannot send

Digital Ocean l Ubuntu

I am having problems with my E-mails, I can receive more to send the E-mail never reaches the recipient. The LOG that presents the following problem:

Mar 29 23:25:28 cyberpanel-ubuntu-s-1vcpu-1gb-nyc1-01 dovecot: imap (contato@mubler.com.br) <11879> <eChqMrW + 5Nl / AAAB>: Logged out in = 96 out = 1013 deleted = 0 expunged = 0 trashed = 0 hdr_count = 0 hdr_bytes = 0 body_count = 0 body_bytes = 0
Mar 29 23:25:57 cyberpanel-ubuntu-s-1vcpu-1gb-nyc1-01 postfix / smtp [11877]: connect to gmail-smtp-in.l.google.com [173.194.205.27]: 25: Connection timed out
Mar 29 23:25:57 cyberpanel-ubuntu-s-1vcpu-1gb-nyc1-01 postfix / smtp [11877]: connect to gmail-smtp-in.l.google.com [2607: f8b0: 400d: c0f :: 1a]: 25: Network is unreachable
Mar 29 23:26:27 cyberpanel-ubuntu-s-1vcpu-1gb-nyc1-01 postfix / smtp [11877]: connect to alt1.gmail-smtp-in.l.google.com [64.233.186.27]: 25: Connection timed out
Mar 29 23:26:27 cyberpanel-ubuntu-s-1vcpu-1gb-nyc1-01 postfix / smtp [11877]: connect to alt1.gmail-smtp-in.l.google.com [2800: 3f0: 4003: c00 :: 1b]: 25: Network is unreachable

I also verified that my port 25 is already open, does it have any configuration that remains to work?