When setting up a Sending Domain for your invitations/triggers etc. you are likely to want to use a domain that closely matches your normal web domains e.g. surveys@example.com and not simply the email address linked to the account which might be linda@marketing.example.com.
However, once you have set up the verified domain and are able to use it from the SmartSurvey App, when used for survey invitations, the Return-Path (the email address that errors are sent to) must point to the SmartSurvey mail servers, at smartsurveyuser.com or amazonses. This is to allow us to track the emails sent out.
Using a Return-Path that doesn't match your sending domain, which is what happens by default, causes "alignment" to be broken and although it is a common scenario for third-party email tools, in the most strict cases, it might cause the email to be scored badly for SPAM. At the very least, it would prevent you from using DMARC to try and apply stricter rules to emails from your domains.
SmartSurvey now allows you to setup a bounce domain that needs to match a sub-domain of your sending domain.
Note: We previously used CNAMEs to implement bounce domains with SmartSurvey but with a move to Amazon SES for email forwarding, this process has changed. The steps below reflect the new way to setup a bounce domain, which Amazon calls a "custom MAIL FROM domain".
You might choose:
Domain: surveys.example.com
Custom MAIL FROM domain: bounce.example.com
If you set this up, when SmartSurvey sends out emails on your behalf, Amazon will append a random identifier to the bounce domain and use that as the Return-Path. This will cause DMARC alignment between your "from" address and Return-Path, allowing you to use a DMARC policy, which will become mandatory in the future, and also reducing the chances of mail going to SPAM.
Amazon treat a lack of DMARC policy and a lack of a custom MAIL FROM domain as high priority issues to be resolved, since they can affect delivery significantly.
Note that DMARC alignment must be set to "relaxed" (the default) in order to permit alignment between the organisational domain (e.g. example.com) and the sub-domain (e.g. bounce.example.com). If your alignment is strict, the policy will fail and the action you specify in the policy will be carried out.
Setting it up is as simple as creating the records displayed in the sending domain page and then pressing verify. If there is a value in the bounce domain box and it does not verify, the domain will not verify. If the box is blank, verification will be skipped and survey invitations will use a SmartSurvey domain for the Return-Path.