Excellent, with 1 thing to fix

frontiersin.org scored 92/100 (grade A). The main issue is DKIM key shorter than 2048 bits. Detected senders: Google Workspace, Microsoft 365, Zendesk and Salesforce.

Checked 2026-10-04 02:18 UTC · fresh check

3 passed1 needs attention0 failing4 for informationDetected senders: Google Workspace, Microsoft 365, Zendesk, Salesforce

All checks

MXCan servers find your inbox?Only one MX hostInfo

Info: Only one MX host
All mail for frontiersin.org goes to frontiersin-org.mail.protection.outlook.com. Most hosted providers make that one name highly available; if you run your own server, consider a backup MX.

SPFWho may send as you?SPF ends in softfail (~all)Info

Info: SPF ends in softfail (~all)
"~all" is common and works well with DMARC. "-all" is stricter; switch when you are sure every sender is listed.

DKIMAre your emails signed?DKIM key shorter than 2048 bitsNeeds attention

Warning: DKIM key shorter than 2048 bits
google (1024-bit), selector1 (1024-bit), s2 (1024-bit), mail (1024-bit) uses an RSA key below 2048 bits. Short keys can be factored and some receivers treat them as weak. Rotate to a 2048-bit key at your sending provider.
Pass: DKIM key published
frontiersin.org publishes a DKIM key under google, selector1, s1, s2, mail.

DMARCWhat happens to fakes?No issues foundPass

Nothing to report.

AlignmentDoes it match your From?No issues foundPass

Nothing to report.

BIMICan inboxes show your logo?No issues foundPass

Nothing to report.

MTA-STSIs mail to you encrypted?No MTA-STS recordInfo

Info: No MTA-STS record
No MTA-STS record at _mta-sts.frontiersin.org. MTA-STS (RFC 8461) makes sending servers require TLS and a valid certificate when delivering to you, which blocks downgrade attacks.
How to fix this

TLS-RPTWill you hear about failures?No TLS-RPT recordInfo

Info: No TLS-RPT record
No TLS reporting record at _smtp._tls.frontiersin.org. TLS-RPT (RFC 8460) tells senders where to send daily reports about failed encrypted deliveries to you.
How to fix this

How to fix it

Publish the MTA-STS recordTXT

Tells sending servers that frontiersin.org publishes an MTA-STS policy at https://mta-sts.frontiersin.org/.well-known/mta-sts.txt. Change the id whenever the policy file changes.

TypeTXT

Name / Host

_mta-sts.frontiersin.org

Some DNS providers want just “_mta-sts” here.

Value

v=STSv1; id=202610040218

Host the MTA-STS policy filepolicy-file

Serve this file over HTTPS with a valid certificate for mta-sts.frontiersin.org. It lists your MX hosts and starts in testing mode; switch to mode: enforce once TLS-RPT reports show no failures.

Location

https://mta-sts.frontiersin.org/.well-known/mta-sts.txt

Contents

version: STSv1
mode: testing
mx: frontiersin-org.mail.protection.outlook.com
max_age: 604800

Set up a TLS report addressinstruction

Sending servers will report TLS failures when delivering to frontiersin.org, which you need before enforcing MTA-STS. The address must accept TLS reports; a DMARC report address does not necessarily do so.

Applies to: _smtp._tls.frontiersin.org

Pick an address that will receive TLS reports: a mailbox you read (for example tls-reports@frontiersin.org, created first) or a TLS reporting service. 2. Publish a TXT record at _smtp._tls.frontiersin.org with the value v=TLSRPTv1; rua=mailto:<that address>.