We began signing outbound mail flows for sonic.net and list.sonic.net several weeks ago and have started to sign all customer owned domains this morning. This should be seamless for most customers, however, in some cases you may receive special instructions from us in order to enable it for your domains. Having aligned DKIM and SPF has become increasingly important to ensure reliable email delivery, especially into large providers like Gmail, Yahoo and Microsoft. We have chosen not to add DMARC records to customer domains at this time.
Please note, that if you use a third-party service provider such as Mailchimp, Constant Contact, Salesforce or Shopify to send email from either your sonic.net or hosted domain you will most likely need to take action to ensure this email will continue to be delivered as expected. Importantly, you will not be able to send mail through a third-party service from a “@sonic.net†address. (These messages can, of course, have a reply-to to your “@sonic.net†address.) If you do use a third-party service, you will need to work with their customer service to ensure your mail flows will not be affected.
Please direct any questions or comments to https://forums.sonic.net