I have a client with a problem I need some help with.
The @icloud.com email from this client is being marked as spam by all recipients. Even when we unspam the email it still goes back to dumping every email from this account into the spam folder. Even marking this account as a VIP doesn’t help.
With other email accounts would be able to check the dkim / spf records but with iCloud.com there is noting I could do. Apple support checked and was not able to solve the problem.
Is your client using the @iCloud.com receiving non-delivery notices from emails he did not send?
This happened at my previously employer. I had a user whose address was used by a spammer as the return address on emails he was sending. Our logs and the info in the bounces showed the mail was not coming from our server but the damage was done. Individuals and domains started marking his mail as spam, but fortunately our domain was not blacklisted.
I had to create a new email address for the users account and routed inbound mail to his new and original address to the same inbox. Eventually the problem went away, after many months.