Letterbook Docs
Connect an email inbox
Route customer email into Letterbook so conversations appear in one queue.
Last updated June 25, 2026
What this guide covers#
Connect the support address customers already use so inbound messages become conversations in Letterbook.
There are two common ways to route support email into Letterbook:
- Forwarding address: your existing mailbox or provider forwards messages to a Letterbook address.
- Gmail integration: Letterbook connects directly to a Gmail or Google Workspace mailbox.
Both options can route email into Letterbook. The right choice depends on where your support mailbox lives, how much mailbox access you want to grant, and whether you can edit forwarding or DNS settings.
Forwarding address versus Gmail integration#
| Setup path | Best for | How inbound mail gets to Letterbook | What you need |
|---|---|---|---|
| Forwarding address | Any email provider, aliases, groups, previous helpdesks, or teams that want minimal mailbox access | Your current provider forwards each support email to a Letterbook-generated address | Permission to add forwarding rules and approve any forwarding verification |
| Gmail integration | Gmail or Google Workspace mailboxes where direct Google authorization is preferred | Letterbook connects to the Google-managed mailbox directly | Permission to authorize the mailbox, and sometimes Google Workspace admin approval |
Forwarding is provider-agnostic. It works even if support mail currently lands in Microsoft 365, a Google Group, an alias, a previous helpdesk, or a DNS-hosted forwarding service. It is a routing setup: mail arrives in the existing system first, then that system forwards it to Letterbook.
The Gmail integration is a direct connection to a Google mailbox. Use it when the support inbox is already a Gmail or Google Workspace mailbox and your team is comfortable authorizing Letterbook through Google-managed permissions.
Which option should you choose?#
Use a forwarding address when:
- Your mailbox is not hosted in Gmail or Google Workspace.
- Your support address is an alias, group, or distribution list.
- You are migrating from another helpdesk and want to forward new tickets into Letterbook.
- You do not want to grant direct mailbox access.
- You need a simple inbound-only path before sending is fully configured.
Use the Gmail integration when:
- Your support inbox is a real Gmail or Google Workspace mailbox.
- You can authorize access to that mailbox.
- Your Google Workspace admin can approve the connection if required.
- You want Letterbook connected directly to the mailbox instead of relying on forwarding rules.
You can still use forwarding with Gmail if direct authorization is not available or if your support address is a Google Group, alias, or other Google-managed address that is easier to forward than connect directly.
Receiving and sending are separate#
Connecting an inbox gets customer messages into Letterbook. Sending replies from your branded address is a separate setup step.
For example, forwarding support@company.com into Letterbook does not automatically prove that Letterbook can send trusted replies as support@company.com. To send replies from that address, configure sender authentication and DKIM in Enable sending from your support address.
Setup steps#
- Pick the customer-facing email address customers already use.
- Confirm where that address currently receives mail.
- Choose forwarding or the Gmail integration.
- Send a test email from an external account.
- Confirm the conversation appears in Letterbook.
- Confirm customer identity, subject, body, and attachments look right.
- Send a test reply.
- Configure sender authentication if replies should come from your support address.
Migration guidance#
If you are moving from another helpdesk, avoid a hard cutover without testing. Run through these checks first:
- New inbound messages arrive in Letterbook.
- The old helpdesk is not also creating or replying to the same ticket.
- Customer replies thread back into the same Letterbook conversation.
- Auto-replies, macros, and rules in the old system are disabled if they would duplicate responses.
- Your team knows which system owns new tickets after launch.
Keep the previous inbox available for historical reference until your team is comfortable with the new workflow, but route new production traffic to one system.
Troubleshooting#
Messages do not appear in Letterbook#
Check whether the email is landing in the original mailbox first. If it is, the problem is usually the forwarding rule or integration authorization. If it is not, check your MX records, mailbox routing, alias rules, or previous helpdesk setup.
The sender looks wrong#
Forwarding should preserve the original customer as the sender. If conversations show the forwarding mailbox instead, your provider may be forwarding as an attachment, rewriting headers, or using a rule that does not preserve the original message.
Replies do not send#
Inbound routing and outbound sending are separate. If receiving works but replies fail, finish the sending setup and DKIM verification for the support address.
Duplicate tickets appear#
Make sure only one route is sending mail into Letterbook. Duplicate conversations usually happen when both a direct integration and a forwarding rule are active for the same mailbox, or when a previous helpdesk still forwards messages.