Outlook.com privacy rating

Summary

Outlook.com scores 36 out of 100 (grade F) on the email providers criteria. It meets 6 of 19 criteria: transparency report, tells users about requests, TLS configuration, open protocols, IMAP support and POP3 support. It partly meets security headers, encrypted mailbox storage, custom domains and SMTP submission. It does not meet open source, no trackers or telemetry, no ads or data sales, independent audit, end-to-end encryption, sign up without personal data, mail transport security, Sender Rewriting Scheme and ARC sealing. It is based in the United States: Five Eyes member; subject to the US CLOUD Act. Automated tests: SSL Labs grade A+ and Mozilla HTTP Observatory grade B+.

Score 36 out of 100. How scoring works

Criteria

• ✖No

  Open source ×3Weight 3 of 3

  Is all the source code needed to run the product public?

  Closed source.

• ✖No

  No trackers or telemetry ×3Weight 3 of 3

  Are the website and apps free of third-party trackers, with any analytics anonymous and any telemetry off by default?

  Microsoft collects usage and diagnostic data and uses data about users for personalized advertising.

  microsoft.com

• ✖No

  No ads or data sales ×2Weight 2 of 3

  Is the product funded without advertising, ad targeting or selling user data?

  The free service shows ads.

  microsoft.com

• ✖No

  Independent audit ×2Weight 2 of 3

  Has an independent security or privacy audit been published within the last three years?

  No independent audit of Outlook.com is published.

• ✔Yes

  Transparency report ×2Weight 2 of 3

  Does the provider regularly publish how many government and legal requests it receives and how it responds?

  Publishes counts of government requests for consumer data, including Outlook.com, twice a year.

  microsoft.com

• ✔Yes

  Tells users about requests ×1Weight 1 of 3

  Does the provider promise to tell users about requests for their data, unless a court forbids it?

  Microsoft gives prior notice to Outlook.com users whose data is requested, except where prohibited by law or in emergencies.

  microsoft.com

• ✖No

  End-to-end encryption ×3Weight 3 of 3

  Can mail be end-to-end encrypted so that the provider cannot read message contents?

  No end-to-end encryption. The Encrypt option for Microsoft 365 subscribers uses keys Microsoft holds.

• ◐Partial

  Encrypted mailbox storage ×3Weight 3 of 3

  Is stored mail encrypted with a key the provider does not hold?

  Data is encrypted at rest with keys Microsoft holds.

  learn.microsoft.com

• ✔Yes

  Open protocols ×2Weight 2 of 3

  Can any standard app connect over IMAP, POP3, SMTP, CalDAV or CardDAV, without extra software?

  IMAP, POP3 and SMTP work with other apps on free and paid accounts.

  support.microsoft.com

• ◐Partial

  Custom domains ×1Weight 1 of 3

  Can mail be sent and received with your own domain?

  Custom domains are supported through Microsoft 365 business plans, not free Outlook.com accounts.

  learn.microsoft.com

• ✖No

  Sign up without personal data ×2Weight 2 of 3

  Can an account be created without a phone number or another email address?

  Creating a Microsoft account asks for personal data such as a birthdate, and a phone number may be requested for verification.

  microsoft.com

• ✖No

  Sender Rewriting Scheme ×1Weight 1 of 3

  Is the envelope sender rewritten with SRS when mail is forwarded, so forwarded mail keeps passing SPF?

  Microsoft documents SRS for Microsoft 365 business mail, not for Outlook.com.

  learn.microsoft.com

• ✖No

  ARC sealing ×1Weight 1 of 3

  Does the provider validate and add ARC (RFC 8617) signatures, so authentication results survive forwarding?

  No published documentation on ARC for Outlook.com. Microsoft's ARC documentation covers Microsoft 365 business mail.

Automated tests

• ✔Yes

  TLS configuration ×2Weight 2 of 3

  Does the website pass the Qualys SSL Labs test with a grade of A or better?

  Grade A+

  ssllabs.com

• ◐Partial

  Security headers ×1Weight 1 of 3

  Does the website pass the Mozilla HTTP Observatory test with a grade of A or better?

  Grade B+ (80/100+)

  developer.mozilla.org

• …Not tested yet

  Modern web standards ×1Weight 1 of 3

  Does the website score 90% or higher on the Internet.nl website test?

  Not tested yet.

• …Not tested yet

  Email security standards ×2Weight 2 of 3

  Does the mail domain score 90% or higher on the Internet.nl email test?

  Not tested yet.

• ✔Yes

  IMAP support ×2Weight 2 of 3

  Does the IMAP server accept connections over implicit TLS on port 993 and advertise IMAP4rev1 or IMAP4rev2 with IDLE push?

  outlook.office365.com:993 (implicit TLS). IMAP4rev1 advertised with IDLE.

• ✔Yes

  POP3 support ×1Weight 1 of 3

  Does the POP3 server accept connections over implicit TLS on port 995 and answer CAPA with UIDL?

  outlook.office365.com:995 (implicit TLS). CAPA: TOP, UIDL, SASL.

• ◐Partial

  SMTP submission ×2Weight 2 of 3

  Does mail submission work over implicit TLS on port 465 with SMTPUTF8, 8BITMIME, PIPELINING and AUTH?

  smtp-mail.outlook.com:587 (STARTTLS). SMTPUTF8, 8BITMIME, PIPELINING and AUTH advertised.

• ✖No

  Mail transport security ×3Weight 3 of 3

  Does the mail domain enforce encrypted, authenticated delivery with MTA-STS, DANE, DNSSEC, TLS-RPT and an enforced DMARC policy?

  Passes: SPF, MTA-STS enforce, TLS-RPT, DNSSEC. Missing: DMARC none, DANE none.

Email standards

• ✔Yes: Mail serversMXoutlook-com.olc.protection.outlook.com
• ✔Yes: RFC 7208 sender policySPFpublished
• ✖No: RFC 7489. Quarantine or reject counts as enforcedDMARCp=none
• ✔Yes: RFC 8461 strict transport securityMTA-STSenforce
• ✔Yes: RFC 8460 TLS failure reportsTLS-RPTpublished
• ✔Yes: RFC 4033 signed DNSDNSSECsigned and validated
• ✖No: RFC 7672 TLSA records on MX hostsDANEnone
• ✖No: Brand logo record (not scored)BIMInone
• ✖No: RFC 6186 and RFC 8314 service records (not scored)SRVnone

Capabilities are what each server advertises before login. How these tests work