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

[jhmkbry_HSoS]

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.