Email Detective — ESP Tracker

Mailchimp

mailchimp.com ↗

🏆Rank #670 🏷 SaaS 🇺🇸United States 📥 Inbox 82%

Mailchimp uses Mailchimp as their primary email service provider. They rank #670 in the Tranco list of most-popular domains. We've also observed sends via Oracle Eloqua. Email goes out from 32 different subdomains. Their email authentication setup is solid (score 100/100).

Marketing ESPMailchimp

Total observations110

Active days42

Avg per active day2.6

Last activity📬 Active · yesterday

Cadence~weekly

Email setup 100/100

Authentication signals observed in this brand's emails. SPF, DKIM and DMARC are the standard sender-authentication stack — see the DMARC policy below for whether spoofing is actually blocked or just monitored. One-click unsubscribe meets Google & Yahoo's bulk-sender requirements.

SPF / DKIM / DMARC above reflect the last 10 emails we've observed. DMARC policy is read live from DNS.

DMARC reports sent to dmarcian. Policy p=reject means receivers actively block or quarantine spoofed mail.

SPF alignment: 49% of observed emails use an aligned return-path (click.mailchimp.com); the rest use third-party paths (mail6.atl51.rsgsv.net, mail239.atl21.rsgsv.net, mail90.usw2001.mcdlv.net) where DMARC has to rely on DKIM alignment.

DKIM alignment: all 81 observed emails sign with a domain aligned with mailchimp.com (mailchimpapp.com, mailchimp.com, send.mailchimpapp.com). DKIM authenticates the visible From — supports DMARC directly.

TLS: modern — 100% TLS 1.3 (across 40 sends).

Delivery: fast — 90% of emails in the last 7 days arrive in under 10 seconds (across 10 sends).

Other ESPs detected

Brands often use multiple ESPs (e.g. one for marketing, another for transactional/notifications).

Confirmed senders

ESPs we've seen sending email for this brand. Green = confirmed by SPF, sender IP rDNS, or known infra pairing (label shows the source). Grey = observed but not yet confirmed by SPF or PTR.

Mailchimp ✓ via Mandrill

Other SPF authorizations

ESPs this brand has authorized in their SPF record. We confirm them with a green ✓ only after seeing recurring use (3+ emails across 2+ days). Until then they stay here — either we haven't observed any email yet, or we've seen a handful but not enough to call them a regular sender for the brand.

Google Workspace Mandrill Responsys SendGrid

Probed: mailchimp.com, click.mailchimp.com, mail174.suw121.mcdlv.net, mail124.sea21.rsgsv.net, mail62.sea91.rsgsv.net, mail112.suw13.rsgsv.net, mandrillapp.com, mail59.suw91.mcdlv.net, mail147.suw16.rsgsv.net, mail35.atl261.mcdlv.net, mail61.suw11.mcdlv.net, mail6.atl51.rsgsv.net

Where emails landed (Gmail)

Folder distribution across all emails from this brand observed in Gmail inboxes. High inbox % = good deliverability; spam appearances are the headline signal.

Where emails landed (Outlook)

Placement observed in Outlook / Microsoft 365 mailboxes. Focused Inbox splits mail into two tabs, "Focused" (inbox) and "Other", plus Junk. 67% reached the Focused inbox across 3 observed emails.

Placement by ESP

Which ESP's emails are landing where. Sorted by spam % so problem senders surface first. Brands using one ESP for marketing and another for transactional often see very different placement profiles per ESP. Per-ESP folder data only started being captured recently — counts here may be smaller than the total above until backfill catches up.

Daily observations per ESP. Brands often run multiple ESPs concurrently — marketing on one, transactional on another — so this chart shows usage rather than switches.

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Sending IPs

IP addresses mailchimp.com has been observed sending from, and where their mail landed in Gmail.

Sending domains