--- title: "Track Performance by Domain, Inbox, and Gmail vs Outlook Recipients" description: "Averages hide the one inbox hurting your whole campaign. Three pivots that find it in ten minutes a week." url: https://warminboxes.com/blog/track-cold-email-performance-by-domain-inbox-provider breadcrumb: "Home > Blog > Track Performance by Domain, Inbox, and Gmail vs Outlook Recipients" --- [WarmInboxes.com](https://warminboxes.com/) [Offer](https://warminboxes.com/offer) [Free Leads](https://warminboxes.com/leads) [Free Tools](https://warminboxes.com/deliverability-tools) [Blog](https://warminboxes.com/blog) [Reviews](https://warminboxes.com/reviews) [Home](https://warminboxes.com/) › [Blog](https://warminboxes.com/blog) › Track Performance by Domain, Inbox, and Gmail vs Outlook Recipients [Back to Blog](https://warminboxes.com/blog) Analytics 5 min read July 20, 2026 # Track Cold Email Performance by Domain, Inbox, and Gmail vs Outlook Recipients Account-wide averages are where problems hide. A healthy 1.8% bounce rate can contain one domain at 6% quietly burning, and a fine reply rate can mask Microsoft recipients getting nothing at all. Here is how to break every metric down by sending domain, individual inbox, and recipient provider, and find the one inbox hurting the whole campaign. [Huzayfa Majeed](https://warminboxes.com/authors/huzayfa-majeed) Cold Email Expert · WarmInboxes ![Breaking down cold email performance by domain, inbox, and provider]() ## Quick Answer: Pivot by Domain, Inbox, and Recipient Provider Export send-level data and pivot bounce, reply, and positive rates by **sending domain → individual inbox → recipient provider** (label recipients Google / Microsoft / gateway / other via MX lookup, free with the [ESP Segmenter](https://warminboxes.com/esp-segmenter)). You are hunting variance: **one inbox at triple the bounce rate, or Microsoft recipients at a fraction of Google's reply rate**. Averages hide both; the pivot finds them in ten minutes a week. ## Why Averages Are Where Campaigns Go to Die Rotation is the reason. Your sequencer spreads sends evenly across the fleet, so one junked inbox does not fail loudly, it dilutes: 10% of your sends quietly landing in spam reads as "reply rate slightly down" at the account level, and the usual response is rewriting copy that was never the problem. The same math applies to recipients: if 40% of your list is Microsoft-hosted and Microsoft is junking you, your blended rate looks mediocre while the truth is one great segment and one dead one. Both diagnoses take one pivot table and both fixes are surgical. ## The Three Cuts, In Order Weekly review, ten minutes CUT 1: by sending domain bounce% | reply% | positive% per domain → one domain elevated? rest it, check blacklists, run the decision tree. CUT 2: by inbox (within suspect domains) same rates per mailbox, 300+ sends before judging → one sibling way off? pull from rotation, rewarm, recheck in 2 weeks. CUT 3: by recipient provider label via MX (ESP Segmenter) → google | microsoft | gateway | other → Microsoft collapse? Outlook playbook + consider MS→MS matching. → gateway silence? expected, isolate segment. Rule: infrastructure fixes before copy fixes, always. The cuts tell you which one you need. - •**Feed it from the same extraction as your [dashboard](https://warminboxes.com/blog/cold-email-dashboard-smartlead-api)**: send rows already carry the inbox; add the recipient's provider label at import time and every future pivot is free. - •**Label recipients once, at list build.** Run every list through the [ESP Segmenter](https://warminboxes.com/esp-segmenter) before launch and store the label as a column; it powers targeting decisions and analytics from the same field. - •**Seed test per domain, not per account,** when a domain looks suspect: the [placement check](https://warminboxes.com/blog/cold-email-opens-high-no-replies) confirms whether the data pattern is a spam-folder problem before you act. - •**Act at the smallest failing unit.** One bad inbox: pull it. One bad domain: rest it ([decision tree](https://warminboxes.com/blog/recover-rest-retire-cold-email-domain)). One bad provider segment: route or reformat for it ([matching evidence](https://warminboxes.com/blog/does-esp-matching-improve-deliverability)). Never nuke a working fleet for a local failure. **The one-inbox story repeats weekly in audits:** a campaign "underperforming for a month" turns out to be eleven healthy inboxes and one that fell into junk in week two, dragging every average down by its rotation share. Ten minutes of pivoting found what four copy rewrites had not touched. Averages are for reporting; variance is for diagnosis. Look at the variance first. ## Frequently Asked Questions ### How do I track cold email performance by domain and inbox? Export send-level data (every send row carries the sending inbox, which implies the domain) from your sequencer's API or CSV export, then pivot: bounce rate, reply rate, and positive rate grouped by sending domain, then by individual inbox. The pattern you are hunting is variance: five domains at 1% bounces and one at 6% means the average lied and one domain needs the recover-rest-retire decision. Sequencer dashboards mostly refuse to show this cut, which is why the export step exists. ### How do I split results by Gmail vs Outlook recipients? MX lookup on every recipient domain: resolve the MX records, label each contact Google (google.com / googlemail.com MX), Microsoft (outlook.com / mail.protection MX), gateway (Proofpoint, Mimecast, Barracuda), or other, then pivot your results by that label. Our free ESP Segmenter does the bulk MX resolution and labeling in one paste. Provider mix explains more campaign mysteries than copy does: a fine blended reply rate often decomposes into strong Google and dead Microsoft. ### What does one bad inbox look like in the data? Its bounce rate runs multiples of its siblings, its replies flatline while others on the same campaign and list segment reply normally, and (if you seed test per inbox) its seeds land in spam while siblings inbox. Because sequencers rotate sends across inboxes evenly, one junked inbox silently drags the whole campaign average down by its share. Pull it from rotation, let it rest and rewarm, and the campaign average recovers without touching copy or list. ### What variance is normal between inboxes on the same domain? Some, small samples are noisy, and an inbox that sent 150 emails will wobble. Judge on volume: at 300+ sends per inbox, a sibling running at half the reply rate or triple the bounce rate of its peers is signal, not noise. Compare like with like, same campaign, same list segment, same period, and use rates, never raw counts, since rotation rarely splits volume perfectly evenly. ### How often should I run this breakdown? Weekly as a standing review, and immediately whenever a campaign underperforms, before touching copy. The decision tree: high bounces concentrated in one domain is an infrastructure problem (rest it); low replies concentrated in Microsoft recipients is a provider problem (see the Outlook playbook and consider provider matching); uniform mediocrity across every cut is finally a message or targeting problem. The breakdown exists to stop you fixing the wrong layer. ## Get FREE .com Domains Prewarmed Inboxes So You Can Send Cold Emails Today [Get Prewarmed & Fresh Inboxes](https://app.warminboxes.com) ## Related Articles [Analytics ### Build a Cold Email Dashboard from the Smartlead API 4 min read](https://warminboxes.com/blog/cold-email-dashboard-smartlead-api)[Deliverability ### Does ESP Matching Improve Deliverability? 5 min read](https://warminboxes.com/blog/does-esp-matching-improve-deliverability)[Deliverability ### Recover, Rest or Retire a Cold Email Domain 5 min read](https://warminboxes.com/blog/recover-rest-retire-cold-email-domain) ## Prewarmed & Fresh Inboxes Google, Microsoft 365 and Azure inboxes with free prewarmed domains and DNS configured before you log in. Prewarmed inboxes send the day they land; every order is delivered within 48 to 72 hours. 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