I have a system that was sending emails perfectly well using the built in smtp server. All of a sudden emails were being delayed by hours. I switched to a google account for email relay and I’m still seeing a delay (not as long but still present). When I checked the email logs I see the following
status=deferred (lost connection with smtp.gmail.com[142.251.4.108] while performing the EHLO handshake)
It will be deferred a few times and then go through about 20 minutes later. Do you think I am looking at a system issue here or a networking/firewall issue?