POP3 session states
01A POP3 session advances through authorization, transaction, and update.
Related RFCs and changes
“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.
DIAGRAM§ 3 ↗
RFC 1939 · § 3EXAMPLE
3 / 3
03
QUIT to update
The server applies deletion processing and ends the session.
Protocol participantThreat or exceptionProtocol controlSimplified drawings · precise section references
RFC 1725RFC 1939 Appendix A
This revision makes USER and PASS optional, requires uppercase +OK/-ERR status indicators, and clarifies command handling.
Read the updated RFC section ↗A successful greeting begins the authorization phase.
- A successful greeting begins the authorization phase.
- After authentication and maildrop locking, transaction commands become available.
- Only QUIT from transaction enters update.
Examples are illustrative. Consult the linked RFC and its errata for implementation details.
Read the RFC section ↗Diagrams simplify the RFC. Read the linked sections for complete requirements.
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