RFC 8461, "SMTP MTA Strict Transport Security (MTA-STS)", September 2018

Errata ID: 6525
Status: Reported
Type: Editorial
Publication Format(s) : TEXT
Reported By: Kaspar Etter
Date Reported: 2021-04-10

Section 4.2 says:

The certificate presented by the receiving MTA MUST not be expired

It should say:

The certificate presented by the receiving MTA MUST NOT be expired

Notes:

NOT should be capitalized.

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