Plains Commerce Bank: email security grade B

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Plains Commerce Bank, Sioux Falls, South Dakota, is the 832nd largest FDIC-insured US bank by total assets ($1.3bn). On 4 November 2026 the public email records of plainscommerce.com graded B: MX pass, SPF pass, DMARC p=none, mail handled by Microsoft 365.

Grade B. One setting does less than it seems to. Read by DNS on 4 November 2026; the records are shown as published.

What was found on plainscommerce.com

Check	Result	What was published
MX	Pass	`99 plainscommerce-com.mail.protection.outlook.com`. Mail handled by Microsoft 365
SPF	Pass	`v=spf1 mx include:spf.cashedge.com include:spf.protection.outlook.com include:_spf.optimalblue.com ip4:50.31.63.161 ip4:159.183.134.171 include:_spf.mailgun.org include:_spf.eu.mailgun.org include:bbemaildelivery.com include:_netblocks.act-on.net ip4:68.171.3.0/24 ip4:66.181.76.40/29 -all`. DNS lookups: 10 of 10 allowed; ends -all
DMARC	Warn	`v=DMARC1; p=none; rua=mailto:itsecurity@plainscommerce.com,mailto:dmarc@99xfpnes.uriports.com; ruf=mailto:dmarc@99xfpnes.uriports.com,mailto:itsecurity@plainscommerce.com; fo=1:d:s`. Policy p=none; reports collected (rua= set)
DKIM	Pass, not graded	Key found on selectors selector1, selector2, s1, s2 (of 10 common selectors tried)

Where Plains Commerce Bank ranks

Plains Commerce Bank is the 832nd largest FDIC-insured US bank by total assets, at $1.3bn as reported to the FDIC (certificate 1678; Sioux Falls, South Dakota). Among the 999 graded banks, Plains Commerce Bank ranks 863rd by grade (ties broken by assets, larger first). In its asset band, $1bn to $10bn, it ranks 722nd of 846; among the 17 graded banks in South Dakota, 14th. 66% of its band and 58.8% of its state graded A.

What this means for the bank

The checker's own notes on each record:

MX, pass: 1 MX record. Replies have somewhere to land. Mail is handled by Microsoft 365.
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: about 10 of the 10 allowed. One more sending service could push it over. This count is an estimate.
DMARC, warn: Policy p=none: receivers are asked to do nothing with mail that fails. Reports are on, so you can see what fails.
DMARC, info: Reports go to itsecurity@plainscommerce.com, dmarc@99xfpnes.uriports.com.
DKIM, pass: DKIM key found at selector1._domainkey.plainscommerce.com, about 1024-bit RSA.
DKIM, pass: DKIM key found at selector2._domainkey.plainscommerce.com, about 2048-bit RSA.
DKIM, pass: DKIM key found at s1._domainkey.plainscommerce.com, about 2048-bit RSA.
DKIM, pass: DKIM key found at s2._domainkey.plainscommerce.com, about 1024-bit RSA.

What this means if you sell to Plains Commerce Bank

Plains Commerce Bank receives mail through Microsoft 365, whose Exchange Online Protection checks every inbound message's SPF, DKIM and DMARC and scores the sender's reputation. A clean, warmed sending domain is the minimum; a failed check lands in junk or is dropped. 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 plainscommerce.com now for today's result. The FDIC's record of the bank is at BankFind, certificate 1678.

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 Plains Commerce 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