This content has been marked as final. Show 3 replies
ALLOW_RECIPIENTS_PER_TRANSACTION causes the tcp_smtp_server to stop accepting more RCTP TO commands, but the client is free to go ahead and send the message to the recipients already accepted and start a new message to the remaining recipients.
The fact that you see Bcc recipients on the message in the Sent folder indicates it was put there by IMAP APPEND (ie, save a copy in the Sent folder) rather than thru the MTA.
Also see the disconnectrecipientlimit channel keyword: