In SM 15, outgoing gateways were priority based and we had the "Sender Priority Override" options. Now, gateways are chosen in the domain settings which is a much better than being priority based but we don't have the "Sender Priority Override". We now have no way to tell SmarterMail to use a different gateway or no gateway at all for specific addresses.
We have customers who use SendGrid, Amazon SES, MailGun, et. al. to ensure better email deliverability. We have SM setup with these as gateways and each domain is configured to use the correct gateway. All of this works just fine and is easier to manage than the old priority-based system. The problem is that some of these customers also use fax services like Nextiva (a VoIP provider) which allows the customer to email FaxNumber@nextivafax.com (e.g. email@example.com) which then turns the emails into faxes and sends them to the Fax Number in the email address. Nextiva (and other providers as well) restrict access to their fax system by email address. They only allow messages from specific addresses. This helps prevent send SPAM faxes. The gateway services change the header of the messages and sends them along, this makes the message not be "from" the email address the fax service is configured to allow. It ends up being from something like FaxNumberfirstname.lastname@example.org.
So, before SM 16, we would set the priority for this special email address to some low priority that was not tied to an outgoing gateway. This would cause SM to send all email for a domain through the gateway except email from this special address. Everything would work just fine with the fax service.
Now, without Sender Priority Override gone and Outgoing Gateways being configured on the domain, we have no way to tell SmarterMail to not use the domain's outgoing gateway for email from specific addresses.
Anybody got any ideas? It's driving our customers nuts.