SMTP AUTH
E34941
SMTP AUTH is an extension to the Simple Mail Transfer Protocol that enables client authentication to mail servers, helping prevent unauthorized use and spam.
Statements (45)
| Predicate | Object |
|---|---|
| instanceOf |
SMTP extension
→
email authentication protocol extension → |
| advertisedBy |
ESMTP
→
|
| advertisedUsing |
EHLO response
→
|
| canUse |
Base64-encoded credentials
→
|
| category |
email security
→
internet standard → |
| compatibleWith |
IPv4
→
IPv6 → |
| definedIn |
RFC 4954
→
|
| extends |
Simple Mail Transfer Protocol
→
|
| fullName |
Simple Mail Transfer Protocol Authentication
→
|
| introduced |
late 1990s
→
|
| negotiates |
authentication mechanism via AUTH parameter
→
|
| operatesAtLayer |
application layer
→
|
| previouslyDefinedIn |
RFC 2554
→
|
| purpose |
authenticate email clients to mail servers
→
help reduce spam → prevent unauthorized use of mail servers → |
| recommendedToBeUsedWith |
TLS encryption
→
|
| relatedTo |
ESMTP
→
STARTTLS → |
| requires |
client support for AUTH command
→
server support for AUTH command → |
| role |
controls relay access on SMTP servers
→
enables submission of email from authenticated users → |
| securityConsideration |
credentials should not be sent in clear text without TLS
→
|
| specifiedAs |
SMTP service extension
→
|
| standardizedBy |
IETF
→
|
| status |
widely deployed on modern mail servers
→
|
| supportsMechanism |
CRAM-MD5
→
DIGEST-MD5 → GSSAPI → LOGIN → NTLM → PLAIN → XOAUTH2 → |
| usedFor |
outgoing mail submission
→
restricting open relays → |
| usedWith |
Mail Submission Agent
→
Mail Transfer Agent → Mail User Agent → |
| usesCommand |
AUTH
→
|
| usesResponseCode |
235 for successful authentication
→
535 for authentication failure → |
Referenced by (1)
| Subject (surface form when different) | Predicate |
|---|---|
|
SMTP
→
|
supportsAuthentication |