# Custom Reply-To **Reply-To Email: Overview and Configuration Guide** ### 1. What the Reply-To setting does The Reply-To setting controls which email address receives replies from recipients. Without a custom setting: * Replies go to the mailbox sender address by default. With custom Reply-To enabled: * Outgoing emails include a `Reply-To` header using your configured custom address. * Recipients who click “Reply” will reply to that custom address instead of the sender address in the `From` header. ### 2. Why this setting exists A custom reply-to address is useful when you’re sending emails through SMTP-only providers such as AWS SES, Mailgun, or SendGrid, which are typically designed for outbound messaging and don’t handle incoming replies. By setting a reply-to address, you can direct all recipient responses to a separate inbox that you control, ensuring you actually receive and manage replies instead of losing them. This is especially important if you’re using a mailbox that supports both SMTP and IMAP, as our system relies on IMAP to sync incoming messages. Configuring a compatible reply-to address allows features like the unified inbox to function properly, giving you full visibility and control over email conversations. This is useful when you want: * A different inbox to receive responses. * A centralized reply mailbox for one or many sender accounts. * Better operational routing of responses without changing the visible sender identity. ### 3. Provider support Custom Reply-To is supported for mailboxes connected though the custom SMTP option, OAuth connections like Zoho and Microsoft aren't supported. Not supported: * Google mailboxes * Microsoft mailboxes * Zoho mailboxes For unsupported providers, the system continues using the sender email behavior. ### 4. Default behavior Default state: * Custom Reply-To is OFF. * Reply behavior uses the sender email address. No action is required unless you want replies routed elsewhere. ### 5. Critical requirement for Unibox sync If you enable custom Reply-To on SMTP: * The custom Reply-To address should be the same mailbox monitored by IMAP for that sender. If they do not match: * Replies may still be delivered to that custom address. * Unibox may not ingest/sync those replies correctly. ### 6. How to configure (single mailbox) 1. Open the mailbox settings for an SMTP mailbox. 2. Go to General Settings. 3. Find the Reply-To section. 4. Enable “Use custom reply-to email”. 5. Enter the custom reply-to email address. 6. Save changes. Validation enforced: * The field cannot be empty when enabled. * The value must be a valid email format. * It must match the IMAP mailbox requirement used for reply ingestion. ### 7. How to configure (bulk update) Bulk General Settings supports custom Reply-To for SMTP selections.
Behavior: * Available only when all selected accounts are SMTP. * If your selection includes non-SMTP accounts, bulk Reply-To update is unavailable. * If you do not edit the Reply-To section, existing Reply-To values are left unchanged. Bulk steps: 1. Select SMTP mailboxes. 2. Open Bulk General Settings. 3. Enable custom reply-to (optional). 4. Enter one custom reply-to email for all selected accounts. 5. Save bulk changes. ### 8. Sending behavior after configuration For SMTP sends: * If custom Reply-To is enabled and non-empty, outgoing email uses that address as `Reply-To`. * Otherwise, it falls back to sender email. This applies to: * Campaign sends * Single/manual SMTP sends * SMTP test-send flows ### 9. Recommended best practices * Use an actively monitored inbox as Reply-To. * Keep Reply-To aligned with the IMAP mailbox used by your inbox sync pipeline. * Test by sending to a personal inbox and clicking Reply. * Confirm replies appear in Unibox before rolling out broadly. * For teams, define a policy for when to use sender email vs shared reply mailbox. ### 10. Troubleshooting Replies are not appearing in Unibox: * Verify custom Reply-To matches the IMAP mailbox configured for that sender. * Verify IMAP credentials and folder mapping are healthy. * Confirm the mailbox is SMTP (feature is SMTP-only). Cannot enable bulk Reply-To: * Check selected accounts. All must be SMTP. Validation error while saving: * Ensure the Reply-To is a valid email address. * Ensure it is not empty when custom Reply-To is enabled. ### 11. Quick FAQ Does custom Reply-To change the From address? * No. It only changes where recipient replies are routed. If custom Reply-To is disabled, what happens? * Reply behavior uses sender email as before. Can I use this on Microsoft/Google/Zoho mailboxes? * No. currently only custom SMTP connections support this. ***