|
Sender
|
Recipient
|
Where does the email go?
|
|---|---|---|
|
Zoom Mail user
|
Someone at a different company or email provider
|
That company's published mail address (MX)
|
| Zoom Mail user |
A user from another Zoom Mail organization (different domain)
|
That domain's published mail address
|
| Zoom Mail user |
A user from another Zoom Mail organization (different domain)
|
Zoom Mail inbound (delivered via MX)
|
| Zoom Mail user | A teammate on the same domain, MX pointing to a gateway or other mail system | That gateway or mail system, not the Zoom mailbox |
| Zoom Calendar | Same-organization Zoom Mail user on a Zoom Calendar domain, and the org uses local calendar delivery | Goes directly to the Zoom mailbox (bypasses public MX) |
| Zoom Calendar | Another Zoom Mail org, default/MX delivery, or any other address | That domain's published mail address |
|
Zoom Scheduler (booking confirmations / ICS files)
|
Anyone
|
That domain's published mail address
|
Note: For shared or hybrid environments: If the domain's MX points to a gateway, archive, or another mail system, user-sent Zoom Mail goes to that system, even if the recipient has a Zoom mailbox. Calendar notifications are the only exception, and only under specific conditions (see the next section).
Exceptions: When email does not follow the default path
These paths can skip public MX. They are not the default for user-sent Zoom Mail.
-
Admin routing rule (change route / host group): matching messages go to a configured host.
- Host group may use MX lookup on that host, or a fixed hostname/IP.
- Off by default unless an admin configures it.
-
Zoom Calendar notifications (invites, updates, cancellations, reminders): follow MX by default.
-
Skip public MX only when all of:
- Originator and recipient are in the same organization.
- Recipient is a Zoom Mail user in a Zoom Calendar domain.
- Recipient organization uses local calendar delivery.
- Cross-org calendar mail, including another Zoom Mail customer, follows MX.
- New organizations are set up with MX calendar delivery, not local.
- Calendar mail to any other address (external attendee, or a domain that is not Zoom Mail + Zoom Calendar) follows MX.
- Zoom Scheduler booking / ICS mail is not this path. It follows MX.
-
Custom outbound routes from transport-rule connectors are not enabled as the production default.
Frequently Asked Questions About Zoom Mail Outbound Delivery
Both users are on Zoom Mail. Why did the message go to our gateway or a different mail server?
User-sent emails and Zoom Scheduler booking emails always use the recipient domain's published MX record. Being on the same platform, or even the same organization, does not automatically keep email inside Zoom Mail.
Calendar notifications are the only type that can bypass the public MX and go directly to a Zoom mailbox, and only when all three conditions are met: the recipient is in the same organization, uses Zoom Mail on a Zoom Calendar domain, and the organization is set to local calendar delivery.
Can we force emails to go directly into Zoom mailboxes without passing through our gateway?
There is no global internal delivery switch for user-sent mail. The available options are:
- Point the domain's MX record directly at Zoom Mail, so inbound mail routes through Zoom.
- Use an admin routing rule to redirect specific outbound email traffic to a designated host.
Does email between Zoom Mail users always stay on Zoom's network?
No, not for user-sent email or Zoom Scheduler booking confirmations. Both follow the recipient domain's published MX record.
Calendar notifications stay in the Zoom mailbox only when the recipient is in the same organization, is a Zoom Mail user on a Zoom Calendar domain, and the organization is configured for local calendar delivery. Cross-organization mail still uses MX, even between two Zoom Mail organizations.
Do calendar invites bypass our gateway in a hybrid or coexistence setup?
Only if all three conditions are met: the recipient is in the same organization, uses Zoom Mail on a domain that also has Zoom Calendar, and the organization is set to local calendar delivery.
They will not bypass the gateway for:
- Users at a different Zoom Mail organization
- Organizations using the default MX-based calendar delivery (including newly created organizations)
- User-sent emails
- Zoom Scheduler booking confirmations and ICS files
All of these still follow the published MX record.