Postfix - timed out while receiving the initial server greeting

I recently discovered this error message in my post mail.log

status=deferred conversation with example.com[255.255.255.255] timed out while receiving the initial server greeting The problem here is that the receiving mail server was not sending the 220 helo response as soon as the connection was made and therefor was timing out due to this setting smtp_helo_timeout = 15s Changing this to 30s seemed to have fixed my issue with the problem receiving mail server. As I understand it this delay in sending the 220 response can be for a number of reasons. Maybe even intentional at times to help avoid spammers who don’t want to wait 30’s for each connection to see if the server is available.