I've had a LF domain for over a year now, which has worked great with an email relay server I have control over. However, I am considering setting up another LF domain which will have to use Gmail mail servers, which I obviously do not have control over. And these aren't just normal XYZ@Gmail.com accounts, it is actually a custom domain that is using Gmail as their email provider. (john@mycompany.com which is actually pointed to a Google mail server) I'm at a loss as to whether this will even work, and if it can work, how do I go about setting this up? I do have complete control over the DNS records for the custom domain, so no issues there. Any help or pointers are appreciated. Thanks.
The relaying over google SMTP service works somehow, but agree it's better to use own SMTP relay server or configure the LF server and DNS forward and reserve records for direct delivery where you have more control over. When you are going to relay over the Google relay service please check this howto: https://support.google.com/a/answer/2956491?hl=en On the LF server in the "Admin > Configuration > Email" I would recommend to enable "Use The Email Sender Address as from address for all emails" option, the "Email Delivery Security Level", should work if you keep the default "May Opportunistic TLS" settings. Then fill in the customer's Gmail Email relay host. In Google's admin console in the Allowed senders section, choice "Only addresses in my domains".
