YOU HAVE SENT NOTIFICATIONS TO YOUR SUPPLIER - BUT THEY NEVER GET THEM
First of all - you should tell your Supplier to check their Spam folder - if the emails from Delogue is in there - they should make sure to mark them as NOT spam.
If that didn't do the trick - please check if the email address to your Supplier is correct and that the Supplier you are notifying is actually marked as Active.
If they still don't get the notifications - then please make sure that your Suppliers email provider has white listed the domain delogue.com and make sure that they have the email address email@example.com on their white list too.
You will have to inform your Supplier about this. So your Supplier can contact their email provider.
We do know that some - especially Chinese email providers - marks emails from firstname.lastname@example.org as spam without any reason. Sometimes they claim the the emails contain illegal content.