Domino: SMTP Multiple 5xx errors are ignored
When a remote SMTP server returns multiple 554 errors to Domino, you will not see a detailed explanation for the rejection
This has been identified as a product enhancement under APAR LO73220.
Recorded in SPR # TPON935JA5 - Enhancement: Ability For Domino To Report On More Than One 5xx Errors From An Smtp Server
Diagnosing the problem
Using debug parameter SMTPClientDebug=1 on the Domino server, you can see that a multiline 554 response are received by Domino
14/12/2012 18:04:33 [0A44:000F-080C] SMTPClient: ReceiveResponse: 554-Transaction failed (id=50CB5C1F10C00000), maximum 8 recipients listed below:
14/12/2012 18:04:33 [0A44:000F-080C] SMTPClient: ReceiveResponse: 554-Address:firstname.lastname@example.org Server: server_ip Command:EODT Error:554 delivery error: dd This user doesn't have a yourserver.com account (email@example.com)  - mail.yourserver.com
14/12/2012 18:04:33 [0A44:000F-080C] SMTPClient: ReceiveResponse: 554 Transaction failed
Rather than concatenating the lines, Domino uses the last line as the reason for the rejection.
This does not contravene RFC821
" In many cases the sender-SMTP then simply needs to search for the reply code followed by <SP> at the beginning of a line, and ignore all preceding lines. "
RFC5321, does not specify to ignore or read all preceding lines.
Resolving the problem