Sending email, especially on behalf of another company, comes with a ton of caveats and recommendations that we try to adhere to in an effort to avoid our domain getting blacklisted and added to spam lists. We made some changes to Ignition, so that all direct client emails would come from the no-reply@ email address.
The response was due to Google announcing a July 2016 launch date where they would start enforcing a strict DMARC policy (ie. rejecting all emails that aren't authorized to come from a nominated domain). The prospect of potentially having all client facing emails not reaching the intended address was enough for us to make some changes.
In a nutshell it's a way for a mail server to check if an email has permission to be able to be send 'from' that domain. You can learn more about this here and here.
The current send email from field simply changes the "from" field in the email, so the display name in the inbox will be the practice name, or the user if you wish to override it on the proposal.
In most email clients, this should display well and give the end user the recognition they need to know its coming from your practice!