This SMTP/LMTP server option sets a limit on the number of messages allowed per connection. The default is no limit. When the number of messages specified is exceeded, then normally the temporary error
451 4.5.3 No more transactions allowed
is returned at the MAIL FROM: line; but see the
TRANSACTION_LIMIT_RCPT_TO TCP/IP-channel-specific option which will cause this temporary error to instead be issued at the RCPT TO: line. See also the
transactionlimit and (in the case of SMTP)
disconnecttransactionlimit channel options, which may be used to set such limits on a per-channel basis (hence providing finer-grained control than the
ALLOW_TRANSACTIONS_PER_SESSION option which applies to all channels handled by the same default Dispatcher SMTP or LMTP service).