Frost Bank: email security grade B

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Frost Bank, San Antonio, Texas, is the 46th largest FDIC-insured US bank by total assets ($54bn). On 4 November 2026 the public email records of frostbank.com graded B: MX pass, SPF pass, DMARC p=none, mail handled by Own mail servers.

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 frostbank.com

Check	Result	What was published
MX	Pass	`10 mail1.frostbank.com`, `100 mail2.frostbank.com`. Mail handled by Own mail servers
SPF	Pass	`v=spf1 include:_spf.frostbank.com include:_bottomline._spf.frostbank.com include:_spf.salesforce.com include:spfhost.messageprovider.com include:_digitalsvcs._spf.frostbank.com -all`. DNS lookups: 9 or more of 10 allowed; ends -all
DMARC	Warn	`v=DMARC1; p=none; rua=mailto:prod_mail_reports@frostbank.com; ruf=mailto:prod_mail_reports@frostbank.com; fo=1; aspf=r;`. Policy p=none; reports collected (rua= set)
DKIM	Pass, not graded	Key found on selectors s1, s2 (of 10 common selectors tried)

Where Frost Bank ranks

Frost Bank is the 46th largest FDIC-insured US bank by total assets, at $54bn as reported to the FDIC (certificate 5510; San Antonio, Texas). Among the 999 graded banks, Frost Bank ranks 676th by grade (ties broken by assets, larger first). In its asset band, $10bn to $100bn, it ranks 88th of 122; among the 86 graded banks in Texas, 67th. 69.7% of its band and 76.7% 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, 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 prod_mail_reports@frostbank.com.
DKIM, pass: DKIM key found at s1._domainkey.frostbank.com, about 2048-bit RSA.
DKIM, pass: DKIM key found at s2._domainkey.frostbank.com, about 2048-bit RSA.

What this means if you sell to Frost Bank

Frost Bank lists MX hosts under its own domain, so it runs or fronts its own mail servers. What filters sit behind them is not visible from DNS; assume they check SPF, DKIM and DMARC like everyone else, and that a bank-run gateway is at least as strict as a commercial one. 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 frostbank.com now for today's result. The FDIC's record of the bank is at BankFind, certificate 5510.

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 Frost 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