We seem to be running into the [oob] bounce issue more frequently. This is when emails sent via Marketo are first recorded as being delivered, but are then quickly recorded as having also bounced due to secondary filtering servers. I'm sure I just grossly oversimplified the issue . Our delivery rates are typically very strong (98+%) and we are on a dedicated IP so overall we typically don't need to spend that much time worrying about deliverability. We also send to 250ok seed lists and typically don't see any issues flagged by their product. These [oob]'s are starting to become a real problem for us though. The reason is because we sync our Email Invalid field data back to CRM so users have some insight on this data (i.e., we want them to update the record w/ the new email address). With the [oob]'s, we hear back from users that the email address being flagged as a false positive invalid is indeed valid because they have been interacting with the email address via Outlook, for example.
I understand the issue and I realize that there's probably not a silver bullet answer for this, but I am wondering what others are doing to address/mitigate this issue? I'm being asked by my CRM admins to identify the false positives and auto flip them back to being valid email addresses, but then we be re-sending to email addresses whose companies are filtering us. I'm guessing that would not be a good idea at scale. I've started to think about introducing a 3rd party verification data source to help with this, but I'm not exactly sure what that would even solve for. Any thoughts, suggestions, approaches, links to discussions with potential solutions for this issue, etc. would be highly appreciated.