Захар Joe's questions

Two interrelated questions:

1. I'm trying to understand if it's not recommended to have a server hostname set to just domain.com instead of host.domain.com (system-wide). One consequence of that for me is that Postfix stops working properly, complaining of user not being found when an email is being received: status=bounced (unknown user: "mailuser") where "mailuser" is a part of [email protected]. I'm not sure of the exact cause of that particular problem (could be that it's tied to Dovecot's user database), but the question is about whether setting the hostname like that is not recommended in general and why.

2. My problem is that I would like to enable SSL certificates for the server on the receiving end and I only have the certificate issued for domain.com and www.domain.com and not host.domain.com. I'm trying to work around that by making postfix reply to HELO with "domain.com" and subsequently present a valid certificate for "domain.com", but haven't found a way to do so without breaking mail delivery. Right now it presents a certificate for "domain.com" while announcing itself as "host.domain.com".

Is there anything in RFCs forbidding me from specifying NS records for mydom.example that go like this:

mydom.example 192.0.2.4
secondaryns.example

as compared to

ns.mydom.example 192.0.2.4
secondaryns.example

Specifically, when the primary NS is on the same domain, can I use mydom.example there or is it strictly necessary to have any third-level domain for NS such as ns.mydom.example?

This is a stock OS X 5.2 Server mail configuration which I'm trying to change to make it reject a spam message with a "554 5.7.0 Reject" before accepting it without sending out any additional non-delivery notifications to the sender. It's configured to accept spam with a "250 2.7.0 Ok" and later discard or quarantine it out of the box. That is usually done with

$final_spam_destiny       = D_REJECT;
$warnspamsender = 0; (probably not necessary)

and can be fine-tuned using

$sa_dsn_cutoff_level = X;
$sa_crediblefrom_dsn_cutoff_level = X;

The problem I'm having is that despite those cutoff levels being way less than the actual spam score for a particular message, the DSN/bounce still gets through. It looks like this:

Oct 25 11:52:18 mailbox postfix/smtpd[52962]: 1CD504D13C96: client=mail.informark.co.ua[85.25.13.92]
Oct 25 11:52:18 mailbox postfix/cleanup[53010]: 1CD504D13C96: message-id=<11a201d22e97$126f7740$2adb3d4f@ynmyfnj>
Oct 25 11:52:19 mailbox postfix/qmgr[52740]: 1CD504D13C96: from=<[email protected]>, size=145530, nrcpt=1 (queue active)
Oct 25 11:52:20 mailbox postfix/smtp[53011]: 1CD504D13C96: to=<[email protected]>, relay=127.0.0.1[127.0.0.1]:10024, delay=2.2, delays=1.1/0/0.02/1, dsn=5.7.0, status=bounced (host 127.0.0.1[127.0.0.1] said: 554 5.7.0 Reject, id=52765-01 - spam (in reply to end of DATA command))
Oct 25 11:52:20 mailbox postfix/bounce[53022]: 1CD504D13C96: sender non-delivery notification: 4B9804D13CB0
Oct 25 11:52:20 mailbox postfix/qmgr[52740]: 1CD504D13C96: removed

Oct 25 11:52:20 mailbox postfix/cleanup[53010]: 4B9804D13CB0: message-id=<[email protected]>
Oct 25 11:52:20 mailbox postfix/qmgr[52740]: 4B9804D13CB0: from=<>, size=3019, nrcpt=1 (queue active)
Oct 25 11:52:20 mailbox postfix/bounce[53022]: 1CD504D13C96: sender non-delivery notification: 4B9804D13CB0
Oct 25 11:52:20 mailbox postfix/smtp[53015]: 4B9804D13CB0: to=<[email protected]>, relay=mail.informark.co.ua[85.25.13.92]:25, delay=0.58, delays=0/0/0.26/0.32, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as 9145D8C8CCC)
Oct 25 11:52:20 mailbox postfix/qmgr[52740]: 4B9804D13CB0: removed

and the relevant part from amavis.log (debug level 5) looks like so:

lookup [forward_method] => true,  "[email protected]" matches, result="smtp:[127.0.0.1]:10025", matching_key="(opaque:smtp:[127.0.0.1]:10025)"
delivery method is 1, recips: [email protected]
get_deadline quar+notif - deadline in 479.0 s, set to 288.000 s
prolong_timer quar+notif: timer 288, was 288, deadline in 479.0 s
DSN: sender NOT credible, SA: 15.417, <[email protected]>
lookup: (scalar) matches, result="-100"
lookup [spam_dsn_cutoff_level_bysender] => true,  "[email protected]" matches, result="-100", matching_key="(constant:-100)"
dsn: . 554 Spam <[email protected]> -> <[email protected]>: on_succ=0, on_dly=1, on_fail=1, never=0, warn_sender=, DSN_passed_on=, destiny=-3, mta_resp: "554 5.7.0 Reject, id=52765-01 - spam"
DSN: FAIL . 554 Spam, status propagated back: <[email protected]> -> <[email protected]>
delivery_status_notification: notif 0 bytes, suppressed: no
one_response_for_all, per_recip_capable: N, suppressed: N
one_response_for_all <[email protected]>: REJECTs, '554 5.7.0 Reject, id=52765-01 - spam'
notif=N, suppressed=0, ndn_needed=, exit=69, 554 5.7.0 Reject, id=52765-01 - spam
get_deadline delivery-notification - deadline in 479.0 s, set to 288.000 s
prolong_timer delivery-notification: timer 288, was 288, deadline in 479.0 s
status counters: InMsgsStatus{Rejected,RejectedInbound}
get_deadline snmp-counters - deadline in 479.0 s, set to 288.000 s
prolong_timer snmp-counters: timer 288, was 288, deadline in 479.0 s
orcpt_encode rfc822, [email protected], smtputf8
oldest_public_ip_addr_from_received: 178.17.170.60
Blocked SPAM {RejectedInbound}, [85.25.13.92]:44462 [178.17.170.60] <[email protected]> -> <[email protected]>, Queue-ID: 1CD504D13C96, Message-ID: <11a201d22e97$126f7740$2adb3d4f@ynmyfnj>, mail_id: N0710n9hpdxw, Hits: 15.417, size: 145530, 1021 ms
get_deadline main_log_entry - deadline in 479.0 s, set to 288.000 s
prolong_timer main_log_entry: timer 288, was 288, deadline in 479.0 s
TIMING-SA total 817 ms - parse: 8 (1.0%), extract_message_metadata: 55 (6.7%), get_uri_detail_list: 1.42 (0.2%), tests_pri_-1000: 32 (3.9%), tests_pri_-950: 1.05 (0.1%), tests_pri_-900: 1.13 (0.1%), tests_pri_-400: 26 (3.1%), check_bayes: 24 (2.9%), b_tokenize: 11 (1.3%), b_tok_get_all: 3.5 (0.4%), b_comp_prob: 4.4 (0.5%), b_tok_touch_all: 0.80 (0.1%), b_finish: 1.12 (0.1%), tests_pri_0: 665 (81.4%), check_dkim_adsp: 479 (58.6%), check_spf: 43 (5.3%), poll_dns_idle: 0.28 (0.0%), check_pyzor: 0.25 (0.0%), tests_pri_500: 5 (0.7%), get_report: 0.77 (0.1%)
updating snmp variables in BDB
get_deadline check done - deadline in 479.0 s, set to 288.000 s
prolong_timer check done: timer 288, was 288, deadline in 479.0 s
sending SMTP response: "554 5.7.0 Reject, id=52765-01 - spam"
ESMTP> 554 5.7.0 Reject, id=52765-01 - spam
...
ESMTP< QUIT\r\n
...
ESMTP> 221 2.0.0 [127.0.0.1] amavisd-new closing transmission channel

As a result despite explicitly telling amavis/postfix NOT to send out a bounce to a faked email address and even amavis acknowledging my wish there, the bounces still get sent out. I presume the key in the logs is the word "suppressed" which is "no" and "0" instead of "yes" and "1" as I have seen in the amavis logs elsewhere on the internet.

So the question is what I'm doing wrong and whether there could be something else interfering with the setup and I'd also like to know the best way to debug this. Obviously the statements in the amavis log are contradictory.