Email delivery failing (have SMTP records showing delivery to comcast but then the email disappears)
Hi - I work with a financial lender, we've noticed a pattern of delivery issues specific to comcast which has worstened over the past few months. Here is one recent example - customer is looking for our loan documents we sent to them. They send an email directly to the address we send loan docs from (to whitelist us) and we receive that email but replies are not received by the customer (sending using salesforce-gmail). Our gateway shows the comcast email gateway accepting our messages (screenshots below) but our customer can not find the emails in spam (in app or in webapp).
Other threads in this forum indicate comcast has a silent black hole that is not visible or configurable to the comcast customer and is not reflected in the email server response to our gateway - comcast says the message will be delivered to the user but instead it goes into a black hole. Is this a thing, and what is the best path forward for us to ensure we have a fair opportunity to do business with comcast customers.
Please note all communications are on-request, there is no marketing here at all, this is happening to our current customers when they request we send them documents, etc.
Please note: some of our communications are legally required, and regulated, if comcast gateways are misconfigured in some way to indicate delivery when in fact they do not deliver, it's imperitive we understand how that works so we can ensure we comply with applicible regulations and laws on our end. For example, we may decide we have to snail-mail all comcast customers if we can not count on gateways to provide reliable delivery information.