Self-hosted: allow one sending domain across multiple workspaces

[jacobgraf]

Scope & Context

We run one self-hosted instance with a workspace per client business. Our team works across these workspaces and sends campaigns as name@ourcompany.com. A sending domain can only be registered in one workspace per instance, so only one workspace can send as ourcompany.com. This makes sense as the default on Twenty Cloud, but on a self-hosted instance one organization owns every workspace.

Current behavior

• Adding an email channel on a domain already used in another workspace fails with "Registered by another workspace."
• EmailingDomainService.createEmailingDomain checks domain against all workspaces and throws EMAILING_DOMAIN_ALREADY_REGISTERED.
• Removing the last email channel on a domain deletes the domain from the provider account (cleanupDomain).

Expected behavior

A verified domain can be used by more than one workspace on a self-hosted instance. Any of these would work:

1. A server setting such as EMAILING_DOMAIN_ALLOW_MULTI_WORKSPACE=true.
2. An admin panel option to share a verified domain with chosen workspaces.

In both cases, the domain is only deleted from the provider when no workspace still uses it.

Technical inputs

• The DNS for a domain is verified once with the provider (Resend domains are account-level), so the limit comes from Twenty's data model, not the provider.
• Relax the global uniqueness check in createEmailingDomain behind the setting, and make deleteEmailingDomainByDomainIfExists and cleanupDomain skip the provider delete while another workspace still uses the domain.

Environment: self-hosted v2.50.0, EMAILING_DOMAIN_DRIVER=RESEND, 5 workspaces

[twenty-eng-sync[bot]]

Kind: feature request. Self-hosted workspaces cannot share a sending domain; registering it in another workspace is rejected.
Proposed severity: UNDEFINED, because the report requests new multi-workspace domain-sharing behavior rather than describing a defect in existing supported behavior.
Root-cause hypothesis (high confidence): packages/twenty-server/src/engine/core-modules/emailing-domain/services/emailing-domain.service.ts enforces global domain uniqueness and invokes remote cleanup when deleting a workspace’s domain.
The report includes the environment and expected behavior; no reproduction steps or screenshots were provided.

[neo773]

Thanks for the detailed suggestion! We understand the use case, but we don't plan to implement this for now. It's a fairly niche requirement, and supporting shared domains across workspaces would add quite a bit of complexity and ongoing maintenance. Our current setup is designed around keeping workspaces separate, so we don't think it's something we can prioritize at the moment. Appreciate you taking the time to explain the problem!