And icloud too. They are very sensitive to ipv6. In case of icloud, I attribute it to the Proofpoint spam filtering system, which also sell service to ups.com.

And icloud too. They are very sensitive to ipv6. In case of icloud, I attribute it to the Proofpoint spam filtering system, which also sell service to ups.com. And even gmail, but at least gmail accept the email, then just flagged it as spam.