In December (a few days before Christmas -> means many recipients probably had activated their Out-Of-Office-Notifications) we published a Mail campaign with a target group of appr. 3.000 contacts (sent via SINCH from SAP Marketing Cloud).
Except of a few soft and hard bounces, we are sure, that most of the 3.000 contacts received our mail successfully.
But we are wondering, that we only got back 2 Out-Of-Office-Mails, which does not make sense regarding a target group of 3.000 contacts.
In a test campaign we sent mails to a small internal group of contacts. A few of them had activated their Out-Of-Office-Mail. Every contact received our mail successfully, but the Out-Of-Office-Mails were not sent to the Reply-to-address saved for our campaign.
Why do we not get all Out-Of-Office-Mails back from our recipients? Is it possible that the mail providers like Outlook are blocking these mails?
As additional information:
Because we have not finished implementing the SAP Marketing Cloud for our customer, the customer currently is still using Inxmail to execute mail campaigns. In these Inxmail Mail campaigns the same Reply-to-address is used and our customer receives all Out-Of-Office-Mails.