Mail servers cannot resolve to my SMTP mail server in google cloud. Can someone please help? Its a mailcow server
Answer
Google Cloud blocks SMTP port 25 egress. This prevents traditional SMTP servers from functioning. You can use other ports such as 465/587 but that is typically used to login to a traditional SMTP server (Gmail, Workplace, O365, Zoho, etc) for email forwarding.
In summary, you cannot host a traditional email server in Google Cloud. You can implement email forwarders.
Attribution
Source : Link , Question Author : Regan Wagner , Answer Author : Jofre
