Hello, I have been searching and searching, and still haven't found a solution. I can receive emails (from every other email) and send them but only to the emails inside the server, but can't send them to outside email accounts (like outlook or gmail), this is what i got from the logs: Code: 2025-10-13T12:36:00.005829-06:00 hostname postfix/smtp[3010739]: warning: DNSSEC validation may be unavailable 2025-10-13T12:36:00.006005-06:00 hostname postfix/smtp[3010739]: warning: reason: dnssec_probe 'ns:.' received a response that is not DNSSEC validated 2025-10-13T12:36:00.035633-06:00 hostname postfix/smtp[3010739]: connect to hotmail-com.olc.protection.outlook.com[52.101.194.5]:25: Connection refused 2025-10-13T12:36:00.037616-06:00 hostname postfix/smtp[3010739]: connect to hotmail-com.olc.protection.outlook.com[52.101.68.13]:25: Connection refused 2025-10-13T12:36:00.038305-06:00 hostname postfix/smtp[3010739]: connect to hotmail-com.olc.protection.outlook.com[52.101.42.11]:25: Connection refused 2025-10-13T12:36:00.041003-06:00 hostname postfix/smtp[3010739]: connect to hotmail-com.olc.protection.outlook.com[52.101.9.1]:25: Connection refused I have set the DNS as the guide:
Your internet service provider or datacenter probably blocks port 25 outgoing. Contact the support of the company that provides internet access for this server or the datacenter where you rented that server or vserver and ask them to open port 25 outgoing in their firewall.
Hello, me again, I was told by the provider of my vps that the outgoing port 25 is open, is there a way to very this? Or what are other reason for not sending emails? they added a DKIM registry but it stills says "Connection refused"
Try to connect to the mail server with telnet: Code: apt install telnet then run Code: telnet hotmail-com.olc.protection.outlook.com 25 or to google Code: telnet gmail-smtp-in.l.google.com 25 If the connection times out, then your provider blocks it. Dkim does not matter here as your server is not able to even connect to the remote mail system.
Ok, so it's not an issue with your mail server config. Your server or VM is not allowed to connect to other mail servers on port 25, which means your ISP or datacenter likely blocks it.
Thank you so much, already told them again to check if the port is blocked, will update again if another thing happens!
