Issue with Inconsistent Delivery of Zoom Emails on Custom Domain (hagdananstepsofservice.org)

Hi everyone,

We’re running into an issue where some accounts under our domain do not receive Zoom emails, while others do.

What’s happening:

• A few users on our domain successfully receive Zoom emails but the zoom email is delivered to the central mail.
• Other users never receive them at all.
• In some cases, our mail server delivery logs (cPanel → Track Delivery) show the Zoom messages as “Accepted.”
• For users who don’t get the emails, they don’t show up in inbox or spam.

Troubleshooting we’ve done so far

• DNS records look good (SPF, DKIM, DMARC all in place).
• SPF includes our mail server IP and Z.com includes:
• v=spf1 ip4:18.136.157.239 include:mailrelay01.jpt1.cloud.z.com include:_spf.z.com ~all
• DKIM is configured and valid.
• DMARC is set to p=none.
• Confirmed whitelisting of Zoom domains + IPs on our server.
• Added filters in cPanel to push Zoom emails to inbox (no effect).
• SpamAssassin scores are extremely low (e.g. -99.2), so not spam-related.
• Hosting provider (Z.com) reviewed DNS and mail routing and said it looks correct. They suggested it could be related to Zoom’s VERP-style bounce address (bounces+<tags>@bounce-sg.zoom.us) being misinterpreted by Exim.

Any guidance would be greatly appreciated. This issue is disrupting our use of Zoom.