With the most recent update to Soapbox, we added platform-wide support for the DomainKeys Identified Mail (DKIM) email authentication method. What the heck does that mean? Emails sent by Soapbox - from notifications to newly registered users to app-specific confirmations for website visitors to administrator-specific emails to...well, basically any email Soapbox ever sends for any purpose whatsoever - will be that much more likely to find their way into the intended inbox of the recipient.
What do you need to do to enable this? Absolutely nothing. It's already in effect and improving email deliverability.