Sim
Well-known member
to determine whether it's responsible for the high complaint rate that we've been seeing
FWIW, it is quite likely that WhatsNewDigest is at least indirectly responsible - it is going to be the number one source of bulk email sends from your site and generates a significant volume of email traffic.
If your mailing list isn't already clean and you aren't already restricting who receives the digest emails - you are naturally going to get a lot of complaints or bounces from each send.
Here is a chart of my daily sending reputation on SparkPost - it drops most Sundays when my digest emails go out and I get an increase in bounces/complaints:
I don't think the emails being sent are themselves invalid - they should all have the one-click unsubscribe header added (make sure you are running XF 2.2.15 and WND 5.0.6) - it will be the volume of emails and who they are being sent to that will be the issue.