St. Louis Bank: email security grade A

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St. Louis Bank, Saint Louis, Missouri, is the 938th largest FDIC-insured US bank by total assets ($1.1bn). On 4 November 2026 the public email records of stlouisbank.com graded A: MX pass, SPF pass, DMARC p=reject, 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 stlouisbank.com

Check	Result	What was published
MX	Pass	`10 usb-smtp-inbound-1.mimecast.com`, `10 usb-smtp-inbound-2.mimecast.com`. Mail handled by Mimecast
SPF	Pass	v=spf1 mx ip4:166.73.7.20 ip4:130.131.194.107 ip4:208.235.248.20 ip4:208.95.206.72/29 include:spf.protection.outlook.com include:relay.mailchannels.net include:_spf.salesforce.com include:sendgrid.net include:amazonses.com ip4:208.93.26.27 ip4:166.73.7.16 ip4:166.73.14.61 ip4:166.73.14.63 ip4:166.73.92.60 ip4:166.73.92.61 ip4:166.73.92.63 ip4:50.58.9.15 ip4:204.95.150.215 ip4:208.66.22.33 ip4:12.108.255.69 ip4:148.163.140.179 ip4:148.163.144.176 ip4:205.220.167.111 ip4:205.220.177.241 ip4:205.220.183.227 ip4:205.220.183.228 ip4:205.220.183.229 ip4:205.220.183.230 ip4:205.220.183.231 ip4:205.220.171.227 ip4:205.220.171.228 ip4:205.220.171.229 ip4:205.220.171.230 ip4:205.220.171.231 include:usb._netblocks.mimecast.com -all. DNS lookups: 9 or more of 10 allowed; ends -all
DMARC	Pass	`v=DMARC1;p=reject;rua=mailto:dmarc@bankonitusa.com;ri=604800;fo=s`. Policy p=reject; reports collected (rua= set)
DKIM	Pass, not graded	Key found on selector k1 (of 10 common selectors tried)

Where St. Louis Bank ranks

St. Louis Bank is the 938th largest FDIC-insured US bank by total assets, at $1.1bn as reported to the FDIC (certificate 58018; Saint Louis, Missouri). Among the 999 graded banks, St. Louis Bank ranks 629th by grade (ties broken by assets, larger first). In its asset band, $1bn to $10bn, it ranks 514th of 846; among the 35 graded banks in Missouri, 19th. 66% of its band and 57.1% 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 9 of the 10 allowed. One more sending service could push it over. 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=reject: receivers are asked to refuse mail that fails.
DMARC, info: Reports go to dmarc@bankonitusa.com.
DKIM, pass: DKIM key found at k1._domainkey.stlouisbank.com, about 1024-bit RSA.

What this means if you sell to St. Louis Bank

St. Louis 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 stlouisbank.com now for today's result. The FDIC's record of the bank is at BankFind, certificate 58018.

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 St. Louis 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