to test I sent an email towards 4 mail addresses as concurrently and I limit 2 concurrent as outbound mail.
I selected DEFER for limit exceeed at the cluebringer.
But the mail server REJECTED a mail due to exceeding limit
Postfixlog;
May 21 16:59:45 postfix1 postfix/smtpd[5635]: connect from unknown[192.168.1.247]
May 21 16:59:46 postfix1 cbpolicyd[4530]: module=Quotas, mode=update, host=192.168.1.247, helo=com2007, from=bulend@test.org, to=malidbulend@gmail.com, reason=quota_update, policy=2, quota=3, limit=4, track=Sender:bulend@test.org, counter=MessageCount, quota=1/2 (50.0%)
May 21 16:59:46 postfix1 postfix/smtpd[5635]: 322061620E6C: client=unknown[192.168.1.247], sasl_method=LOGIN, sasl_username=bulend@test.org
May 21 16:59:48 postfix1 cbpolicyd[4576]: module=Quotas, mode=update, host=192.168.1.247, helo=com2007, from=bulend@test.org, to=bulend.malid@test.net.tr, reason=quota_update, policy=2, quota=3, limit=4, track=Sender:bulend@test.org, counter=MessageCount, quota=2/2 (99.8%)
May 21 16:59:50 postfix1 cbpolicyd[30809]: module=Quotas, mode=update, host=192.168.1.247, helo=com2007, from=bulend@test.org, to=bulend@test.net.tr, reason=quota_update, policy=2, quota=3, limit=4, track=Sender:bulend@test.org, counter=MessageCount, quota=3/2 (149.4%)
May 21 16:59:52 postfix1 cbpolicyd[30194]: module=Quotas, action=defer, host=192.168.1.247, helo=com2007, from=bulend@test.org, to=ymmalid@hotmail.com, reason=quota_match, policy=2, quota=3, limit=4, track=Sender:bulend@test.org, counter=MessageCount, quota=4/2 (198.8%)
May 21 16:59:52 postfix1 postfix/smtpd[5635]: 322061620E6C: reject: RCPT from unknown[192.168.1.247]: 450 4.7.1 <ymmalid@hotmail.com>: Recipient address rejected: limitexceed; from=<bulend@test.org> to=<ymmalid@hotmail.com> proto=ESMTP helo=<com2007>
May 21 16:59:54 postfix1 postfix/cleanup[5648]: 322061620E6C: message-id=<055b01cd3759$fa8660a0$ef9321e0$@test.org>
May 21 16:59:54 postfix1 postfix/qmgr[4260]: 322061620E6C: from=<bulend@test.org>, size=2731, nrcpt=3 (queue active)
May 21 16:59:54 postfix1 postfix/smtpd[5658]: connect from localhost[127.0.0.1]
May 21 16:59:54 postfix1 postfix/smtpd[5658]: 3E8301620E71: client=localhost[127.0.0.1]
May 21 16:59:54 postfix1 postfix/cleanup[5648]: 3E8301620E71: message-id=<055b01cd3759$fa8660a0$ef9321e0$@test.org>
May 21 16:59:54 postfix1 postfix/smtpd[5659]: connect from localhost[127.0.0.1]
May 21 16:59:54 postfix1 postfix/smtpd[5659]: 4249A1620E79: client=localhost[127.0.0.1]
May 21 16:59:54 postfix1 postfix/cleanup[5660]: 4249A1620E79: message-id=<055b01cd3759$fa8660a0$ef9321e0$@test.org>
May 21 16:59:54 postfix1 postfix/smtpd[5658]: disconnect from localhost[127.0.0.1]
May 21 16:59:54 postfix1 postfix/qmgr[4260]: 3E8301620E71: from=<bulend@test.org>, size=3143, nrcpt=1 (queue active)
May 21 16:59:54 postfix1 postfix/qmgr[4260]: 4249A1620E79: from=<bulend@test.org>, size=3151, nrcpt=1 (queue active)
May 21 16:59:54 postfix1 amavis[26280]: (26280-15) Passed CLEAN, LOCAL [192.168.1.247] [192.168.1.247] <bulend@test.org> -> <malidbulend@gmail.com>, Message-ID: <055b01cd3759$fa8660a0$ef9321e0$@test.org>, mail_id: byVWk3gnNYRF, Hits: -, size: 2731, queued_as: 3E8301620E71, 200 ms
May 21 16:59:54 postfix1 postfix/smtp[5654]: 322061620E6C: to=<malidbulend@gmail.com>, relay=127.0.0.1[127.0.0.1]:10024, delay=8.5, delays=8.3/0/0/0.2, dsn=2.0.0, status=sent (250 2.0.0 from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as 3E8301620E71)
May 21 16:59:54 postfix1 postfix/smtpd[5659]: disconnect from localhost[127.0.0.1]
May 21 16:59:54 postfix1 amavis[26279]: (26279-16) Passed CLEAN, LOCAL [192.168.1.247] [192.168.1.247] <bulend@test.org> -> <bulend.malid@test.net.tr>, Message-ID: <055b01cd3759$fa8660a0$ef9321e0$@test.org>, mail_id: bnihhcOX+g9Q, Hits: -, size: 2731, queued_as: 4249A1620E79, 254 ms
May 21 16:59:54 postfix1 postfix/smtp[5655]: 322061620E6C: to=<bulend.malid@test.net.tr>, relay=127.0.0.1[127.0.0.1]:10024, delay=8.6, delays=8.3/0.01/0/0.26, dsn=2.0.0, status=sent (250 2.0.0 from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as 4249A1620E79)
May 21 16:59:54 postfix1 postfix/smtpd[5658]: connect from localhost[127.0.0.1]
May 21 16:59:54 postfix1 postfix/smtpd[5658]: 6D7811620E74: client=localhost[127.0.0.1]
May 21 16:59:54 postfix1 postfix/cleanup[5648]: 6D7811620E74: message-id=<055b01cd3759$fa8660a0$ef9321e0$@test.org>
May 21 16:59:54 postfix1 postfix/qmgr[4260]: 6D7811620E74: from=<bulend@test.org>, size=3137, nrcpt=1 (queue active)
May 21 16:59:54 postfix1 amavis[26280]: (26280-16) Passed CLEAN, LOCAL [192.168.1.247] [192.168.1.247] <bulend@test.org> -> <bulend@test.net.tr>, Message-ID: <055b01cd3759$fa8660a0$ef9321e0$@test.org>, mail_id: vNM+0Uf+T4PJ, Hits: -, size: 2731, queued_as: 6D7811620E74, 153 ms
May 21 16:59:54 postfix1 postfix/smtp[5654]: 322061620E6C: to=<bulend@test.net.tr>, relay=127.0.0.1[127.0.0.1]:10024, delay=8.7, delays=8.3/0.21/0/0.16, dsn=2.0.0, status=sent (250 2.0.0 from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as 6D7811620E74)
May 21 16:59:54 postfix1 postfix/qmgr[4260]: 322061620E6C: removed
May 21 16:59:55 postfix1 postfix/smtp[5661]: 3E8301620E71: to=<malidbulend@gmail.com>, relay=gmail-smtp-in.l.google.com[173.194.70.26]:25, delay=1.3, delays=0.12/0.01/0.27/0.93, dsn=2.0.0, status=sent (250 2.0.0 OK 1337608793 l8si11001560wiw.14)
May 21 16:59:55 postfix1 postfix/qmgr[4260]: 3E8301620E71: removed
May 21 16:59:55 postfix1 postfix/smtp[5664]: 6D7811620E74: to=<bulend@test.net.tr>, relay=mailhub2.test.net.tr[192.168.128.252]:25, delay=1.2, delays=0.08/0.01/0.62/0.52, dsn=2.0.0, status=sent (250 ok 1337608793 qp 69243)
May 21 16:59:55 postfix1 postfix/qmgr[4260]: 6D7811620E74: removed
May 21 16:59:56 postfix1 postfix/smtpd[5635]: disconnect from unknown[192.168.1.247]
May 21 16:59:57 postfix1 postfix/smtp[5662]: 4249A1620E79: to=<bulend.malid@test.net.tr>, relay=mailhub2.test.net.tr[192.168.128.252]:25, delay=3.7, delays=0.11/0.01/3.5/0.03, dsn=2.0.0, status=sent (250 ok 1337608795 qp 69257)
May 21 16:59:57 postfix1 postfix/qmgr[4260]: 4249A1620E79: removed