> For clean Markdown content of this page, append .md to this URL. For the complete documentation index, see https://docs.postnuvia.com/llms.txt.

# Knowledge Base

## Getting Started

#### [What is PostNuvia?](/knowledge-base/what-is-postnuvia)

How PostNuvia compares to Resend, SendGrid, and other email providers.

#### [What can I do with an inbox?](/knowledge-base/inbox-capabilities)

CC, BCC, forwarding, threading, attachments, labels, IMAP, and more.

#### [Creating your first inbox](/knowledge-base/creating-first-inbox)

Get up and running with your first PostNuvia inbox.

#### [Inbox profile pictures](/knowledge-base/inbox-profile-pictures)

Google account photos, BIMI logos, and certificate requirements.

#### [Getting your API key](/knowledge-base/getting-api-key)

How to create and manage your API keys.

#### [Claiming your agent's inbox](/knowledge-base/claiming-agent-inbox)

Take ownership of an inbox your agent created without your email.

## Agent Patterns

#### [Handling inbound emails](/knowledge-base/handling-inbound-emails)

Webhooks vs WebSockets vs polling for receiving emails.

#### [Allowlists & blocklists](/knowledge-base/allowlists-blocklists)

Control who can send to and receive from your inboxes.

#### [Managing threaded conversations](/knowledge-base/threaded-conversations)

Build agents that maintain context across email threads.

#### [Human-in-the-loop workflows](/knowledge-base/human-in-the-loop)

Add human review and approval steps to your agent workflows.

#### [Pods for multi-tenant email](/knowledge-base/pods-multi-tenant)

Isolate inboxes and data across tenants with Pods.

#### [Using labels to track state](/knowledge-base/labels-track-state)

Use labels to manage agent workflow state on emails.

## Domains & Deliverability

#### [Custom domain setup](/knowledge-base/custom-domain-setup)

Send emails from your own domain instead of @postnuvia.com.

#### [SPF, DKIM, and DMARC setup](/knowledge-base/spf-dkim-dmarc)

Authenticate your domain for better deliverability.

#### [Emails going to spam](/knowledge-base/emails-going-to-spam)

Troubleshoot and fix spam folder placement issues.

#### [Domain warming schedule](/knowledge-base/domain-warming)

Gradually build sending reputation on a new domain.

#### [MX record conflicts](/knowledge-base/mx-record-conflicts)

Add PostNuvia DNS records without breaking existing email.

#### [Warming up your inbox](/knowledge-base/warming-up-your-inbox)

Connect to third-party warm-up tools before running cold outbound.

## Troubleshooting

#### [Rate limits](/knowledge-base/rate-limits)

Understand PostNuvia's rate limits and how to work within them.

#### [Preventing duplicate sends](/knowledge-base/preventing-duplicate-sends)

Use idempotency to avoid sending the same email twice.

#### [Domain not verifying](/knowledge-base/domain-not-verifying)

What to do when your domain verification is stuck.

#### [Emails bouncing](/knowledge-base/emails-bouncing)

Diagnose and resolve email bounce issues.

#### [Email spoofing protection](/knowledge-base/inbound-emails-missing)

How PostNuvia protects your inboxes from unauthenticated senders.

## DNS Guides

Step-by-step instructions for verifying your domain with popular DNS providers.

#### [Cloudflare DNS Guide](/knowledge-base/dns-cloudflare)

Configure PostNuvia DNS records in Cloudflare.

#### [GoDaddy DNS Guide](/knowledge-base/dns-godaddy)

Configure PostNuvia DNS records in GoDaddy.

#### [Route 53 DNS Guide](/knowledge-base/dns-route53)

Configure PostNuvia DNS records in AWS Route 53.

#### [Namecheap DNS Guide](/knowledge-base/dns-namecheap)

Configure PostNuvia DNS records in Namecheap.