Sending domains

A sending domain is the domain in the From header of your emails — for example, mail.yourcompany.com or newsletters.brand.io. Most email programs use one or more subdomains for sending so that reputation is isolated from the main website domain.

InboxEagle tracks every sending domain it detects in your campaigns and provides per-domain authentication rates, volume data, and deliverability signals.

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Accessing sending domain data

• From the deliverability dashboard — The domain list appears below the metric cards. Click any row to open the detail view.
• From a campaign — In the campaign history detail view, click the sending domain to jump to its detail page.
• Direct URL — Navigate to app.inboxeagle.com/deliverability-dashboard and click a domain in the sending domains panel.

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Sending domain list

The domain list shows all domains observed within the selected date range, ordered by send volume (highest first). For each domain:

Column	Description
Domain	The sending domain (e.g. mail.yourcompany.com)
Inbox rate	Average inbox placement rate for this domain
Spam rate	Average spam placement rate
Auth rate	Percentage of emails that pass SPF, DKIM, and DMARC
Volume	Number of emails observed from this domain
First seen / Last seen	Date range of observed activity

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Domain detail view

Clicking a domain opens its detail page with these sections:

Authentication status

Three gauges show the authentication pass rates for this specific domain:

Metric	What to aim for	What failing means
SPF pass rate	> 98%	SPF record is missing, malformed, or too permissive
DKIM pass rate	> 98%	DKIM selector is misconfigured or the signing key has changed
DMARC pass rate	> 95%	Alignment failure — SPF or DKIM domain does not match the From domain

Any of these below 95% requires immediate investigation. See Authenticate your sending domain for step-by-step remediation.

Volume trend

A chart shows daily send volume for this domain over the selected period. Use this to:

• Confirm your expected send schedule matches observed volume
• Spot unexpected sends (could indicate a compromised account or misconfigured automation)
• Identify volume spikes that might affect IP warm-up plans

Provider placement

A breakdown of inbox, promotion tab, and spam placement rates by mailbox provider (Gmail, Yahoo, Outlook, AOL) for this domain. This is the same view as the campaign detail, but aggregated across all campaigns from this domain.

Associated IPs

The list of IP addresses from which this domain has sent emails. Click any IP to open its reputation detail view.

If a domain shows poor placement rates but authentication is healthy, the associated IPs may be the cause — especially for shared IP pools.

Email send history

The last 50 campaigns sent from this domain, with subject lines, dates, and placement rates. This is the same data as campaign history filtered to this domain.

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Understanding subdomain strategies

Most professional email senders use a subdomain (e.g. mail.yourcompany.com) rather than the root domain (e.g. yourcompany.com) for transactional and marketing email. This isolates sending reputation from the domain used for your website.

Common patterns:

Pattern	Example	Use case
Single subdomain	mail.yourcompany.com	All sending from one subdomain
Separated by type	news.yourcompany.com, alerts.yourcompany.com	Marketing vs transactional separated
Separated by region	us.yourcompany.com, eu.yourcompany.com	Multi-region sends
Separated by brand	mail.brand-a.com, mail.brand-b.com	Agency or multi-brand operation

Note

Each subdomain builds its own reputation independently. If you send very low volume from a subdomain, mailbox providers may have insufficient data to build a reputation signal — in this case, the root domain reputation is used as a fallback. For very low-volume transactional sends, using the same subdomain as your marketing email (rather than a separate one) may actually give better reputation signals.

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Domain authentication best practices

For each sending domain, ensure:

1. SPF record exists in DNS and includes all authorized sending services
2. DKIM selector is published in DNS and matches the key used by your ESP
3. DMARC policy is set (start with p=none for monitoring, then move to p=quarantine or p=reject)
4. DMARC alignment — the domain in SPF and/or DKIM must match the From domain (relaxed alignment accepts subdomains)

See Authenticate your sending domain for full setup instructions including DNS record examples.

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Adding a domain for tracking

InboxEagle automatically discovers sending domains from:

• Your connected Klaviyo campaigns
• Emails ingested through Gmail sync
• SES events from Bot Finder

You do not need to manually register sending domains. They appear automatically once InboxEagle observes emails sent from them.

To track a competitor’s or brand’s sending domain:

1. Go to Browse → Brands and search for the brand
2. Click Track to add it to your tracked brands
3. Their sending domains will appear in your deliverability dashboard

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Next steps

• Campaign history — Per-campaign placement data
• IP reputation — IP-level health for IPs associated with this domain
• Authenticate your sending domain — Fix SPF, DKIM, DMARC issues
• Deliverability dashboard overview — Aggregate view

View sending domains →