Support: send email replies from the responding agent’s verified work address

Feature request

Is your feature request related to a problem?

PostHog Support currently sends replies using the email address configured for the ticket’s email channel.

For a shared support inbox such as support@company.com, this means every reply comes from the shared address, regardless of which support agent wrote it. Customers cannot easily see who is helping them, and agents cannot reply using their individual work identities such as agent@company.com.

We want incoming support emails to continue going to the shared support@ address and appearing in one PostHog inbox, while outbound replies identify the individual agent who responded.

Describe the solution you'd like

Allow PostHog Support agents to send email replies from their individual, verified organization email addresses.

Example:

• Customer sends an email to support@company.com.
• The email creates a ticket in the shared PostHog Support inbox.
• Agent Jane responds in PostHog.
• The customer receives the response from Jane Smith <jane@company.com>.
• The customer’s reply still returns to the same PostHog ticket.

Suggested behavior:

• Administrators can enable agent-specific sending for an email channel.
• Each PostHog organization member can have a sender identity consisting of:
  • Display name
  • Work email address
• The composer clearly shows the final From and Reply-To addresses before sending.
• The agent’s identity is recorded in the ticket activity history.
• Customer replies remain attached to the original ticket.
• Existing CC participants and email threading are preserved.
• The shared channel address remains the fallback when the responding agent has no configured sender identity.

A possible email structure would be:

Describe alternatives you've considered

• Reply from Gmail instead of PostHog: the response and subsequent customer messages may no longer remain synchronized with the PostHog ticket.

Additional context

We use a shared Google Workspace support address as the inbound channel, but our support workers also have individual company email addresses.

The desired model is:

• One shared incoming address and PostHog inbox.
• Individual verified agent identities for outgoing replies.
• All subsequent customer replies remain attached to the original PostHog ticket.

PostHog Cloud, EU region.

Debug info

- [x] PostHog Cloud

Start by tracing the existing PostHog Support email-channel reply flow and how ticket threading, CC participants, and activity history are handled. Review the current sender configuration and composer behavior before deciding where agent identities and verification belong. Done means verified agent-specific From and Reply-To values work without breaking shared-channel fallback or ticket threading.