[zdware]

I worked at a company that used Proofpoint. Often had to reach out to get emails out of quarantine, etc.

Have you tried contacting the customer and asking them to have their IT team allowlist you?

Had similar issues with Yahoo/AOL.

[internet1776]

Customer service do not entertain us because we are not Proofpoint active customer. Only way to get in touch with us is a dynamic URL generated by them for our IP address. We filled it out immediately about two month ago but they did not respond. It seems like a black hole.