How to read full SMTP transcripts for errors?

Reading SMTP transcripts reveals exactly what happened:

Transcript structure:

Client commands (EHLO, MAIL FROM, RCPT TO, DATA). Server responses (codes + text). Back-and-forth conversation. Final outcome.

Key elements to track:

Connection: Did server respond? With what greeting? EHLO response: What capabilities advertised? MAIL FROM: Accepted or rejected? RCPT TO: Each recipient's status. DATA: Final acceptance or rejection.

Error identification:

Note where 4xx or 5xx first appears. Read full response text. Extract enhanced codes. Identify rejecting server.

Diagnostic value:

Shows exactly which step failed. Provides complete error message. Reveals server identity. Enables precise troubleshooting.

SMTP transcripts are the complete conversation. Every detail of what was said and responded is there.