@SuchMuch The TXT record which you added for pepipost._domainkey.[SUB-DOMAIN] is being used for DKIM signing also. Hence, you should not remove those records.
Here the documentation on how to create a sub-domain and what all DNS configuration to be done: http://support.pepipost.com/knowledge_base/topics/how-to-set-custom-envelope-sender-slash-return-path-address-and-dkim
@SuchMuch During signup, we recommend adding an email address which is non-Gmail, yahoo etc. e.g. something@yourcompany.com instead of something@gmail.com
@Floyd R Turbo The feature is still there, actually we are upgrading this to improve the user experience to minimise the implementation time and of course to minimise the interactions over chat support :)
Backend changes are released but during that time the frontend option was not available...
You can checkout Pepipost. Here is the quick Xenforo-Pepipost integration guide: http://support.pepipost.com/knowledge_base/topics/xenforo/
And, here is the exclusive 100 Million offer for all Xenforo community members:
https://xenforo.com/community/threads/save-20-000-on-your-email-budget.120717/
You can integrate your Xenforo setup with Pepipost SMTP to deliver the emails. By doing this you will be able to track the email opens, clicks, bounces, unsubscribes and abuse complaints all in Real Time.
Here is the quick Pepipost-Xenforo integration guide...