Core Bank: email security grade A

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Core Bank, Omaha, Nebraska, is the 972nd largest FDIC-insured US bank by total assets ($1.1bn). On 4 November 2026 the public email records of corebank.com graded A: MX pass, SPF pass, DMARC p=quarantine, mail handled by Mimecast.

Grade A. Nothing in the records will stop mail. Read by DNS on 4 November 2026; the records are shown as published.

What was found on corebank.com

Check	Result	What was published
MX	Pass	`10 us-smtp-inbound-1.mimecast.com`, `10 us-smtp-inbound-2.mimecast.com`. Mail handled by Mimecast
SPF	Pass	`v=spf1 include:us._netblocks.mimecast.com include:_spf.salesforce.com include:spfhost.messageprovider.com include:servers.mcsv.net include:amazonses.com include:spf.meridianlink.com ip4:207.45.164.0/24 ip4:208.63.79.95 ip4:216.58.237.101 ip4:74.51.216.226 ip4:74.126.60.34 ip4:209.112.104.1/22 ip4:64.207.216.1/22 ip4:162.248.184.1/22 ip4:54.240.32.183 ip4:209.208.209.1/24 ip4:149.72.128.180 ip4:209.34.255.0/24 ip4:44.214.246.148/32 ip4:172.171.88.83 ip4:159.183.10.115 ip4:208.81.32.0/22 -all`. DNS lookups: 7 or more of 10 allowed; ends -all
DMARC	Pass	`v=DMARC1; p=quarantine; rua=mailto:f1ee17a1c995927@rep.dmarcanalyzer.com; ruf=mailto:f1ee17a1c995927@for.dmarcanalyzer.com; fo=1`. Policy p=quarantine; reports collected (rua= set)
DKIM	Pass, not graded	Key found on selectors s1, s2 (of 10 common selectors tried)

Where Core Bank ranks

Core Bank is the 972nd largest FDIC-insured US bank by total assets, at $1.1bn as reported to the FDIC (certificate 34363; Omaha, Nebraska). Among the 999 graded banks, Core Bank ranks 653rd by grade (ties broken by assets, larger first). In its asset band, $1bn to $10bn, it ranks 538th of 846; among the 22 graded banks in Nebraska, 14th. 66% of its band and 77.3% of its state graded A.

What this means for the bank

The checker's own notes on each record:

MX, pass: 2 MX records. Replies have somewhere to land.
SPF, pass: One SPF record, ending in -all (fail): mail from a server that is not on the list should be rejected.
SPF, info: DNS lookups: at least 7 of the 10 allowed. This count is an estimate.
SPF, info: The record uses SPF macros, which only resolve for a real message, so the lookup count is a floor.
DMARC, pass: Policy p=quarantine: receivers are asked to put mail that fails in spam.
DMARC, info: Reports go to f1ee17a1c995927@rep.dmarcanalyzer.com.
DKIM, pass: DKIM key found at s1._domainkey.corebank.com, about 2048-bit RSA.
DKIM, pass: DKIM key found at s2._domainkey.corebank.com, about 1024-bit RSA.
DKIM, info: 8 of the selector lookups failed, so a key may have been missed.

What this means if you sell to Core Bank

Core Bank routes inbound mail through Mimecast, a filtering gateway. Expect strict inbound filtering: a message from a sender whose SPF, DKIM or DMARC fails, or whose domain has little sending history, is unlikely to reach a person. Before you send, run your own domain through the email setup checker and publish a policy with the DMARC record generator. For how a bank buys, see the selling to banks playbook.

Check it live

The records above are from 4 November 2026. Run the same check on corebank.com now for today's result. The FDIC's record of the bank is at BankFind, certificate 34363.

This page is one of 1,000 in the Bank Email Readiness Index Q4 2026, published 4 November 2026 and re-read every quarter; the next edition is due 2 February 2027. If you work at Core Bank and the records have changed, email moe@roimaxi.com and we will re-check and update this page.

ROI Maximizer is a trading name of M Ventures LTD, registered in England and Wales, company no. 15554493. Registered office: 4 Beau Street, Bath BA1 1QY, United Kingdom. moe@roimaxi.com