I have customers using shopify (and other external online services) that send notifications with email addresses of the customer's domain (ie. FROM notification@domain.com TO neworder@domain.com) Those notifications come from shopify relay servers but get bounced when reaching smartermail with 550 autehtication error even when the domain's SPF record is correct allowing mail from the shopify servers. (using the include: feature of the spf record)
I guess we could whitelist all shopify ips, but not the best solution in my opinion.
I would understand that SPF records would check whether its coming from a valid IP/domain and override the "Enable domain's SMTP auth setting for local deliveries" option, right?
Any way to solve this? Any ideas? Thanks in advance.