From: "Peter Moylan" Received: from [192.168.100.201] (HELO mail.2rosenthals.com) by 2rosenthals.com (CommuniGate Pro SMTP 5.4.10) with ESMTP id 12900553 for ecs-isp@2rosenthals.com; Wed, 23 Apr 2025 20:18:24 -0400 Received: from secmgr-va.2rosenthals.com ([50.73.8.217]:33050 helo=mail2.2rosenthals.com) by mail.2rosenthals.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1u7kII-000000007Gj-1iwl for ecs-isp@2rosenthals.com; Wed, 23 Apr 2025 20:18:24 -0400 Received: from pmoylan.org ([144.6.37.71]:60485 helo=mail.pmoylan.org) by mail2.2rosenthals.com with esmtp (Exim 4.97.1) (envelope-from ) id 1u7kIE-000000004jA-1el3 for ecs-isp@2rosenthals.com; Wed, 23 Apr 2025 20:18:20 -0400 X-SASI-Hits: BODYTEXTP_SIZE_3000_LESS 0.000000, BODY_ENDS_IN_URL 0.000000, BODY_SIZE_1700_1799 0.000000, BODY_SIZE_2000_LESS 0.000000, BODY_SIZE_5000_LESS 0.000000, BODY_SIZE_7000_LESS 0.000000, CTE_7BIT 0.000000, DKIM_ALIGNS 0.000000, DKIM_SIGNATURE 0.000000, HTML_00_01 0.050000, HTML_00_10 0.050000, IN_REP_TO 0.000000, KNOWN_MSGID 0.000000, LEGITIMATE_SIGNS 0.000000, MSG_THREAD 0.000000, NO_URI_HTTPS 0.000000, REFERENCES 0.000000, SENDER_NO_AUTH 0.000000, SINGLE_URI_IN_BODY 0.000000, SUSP_DH_NEG 0.000000, TO_IN_SUBJECT 0.500000, USER_AGENT 0.000000, __ANY_URI 0.000000, __BODY_NO_MAILTO 0.000000, __BOUNCE_CHALLENGE_SUBJ 0.000000, __BOUNCE_NDR_SUBJ_EXEMPT 0.000000, __COURIER_PHRASE 0.000000, __CP_URI_IN_BODY 0.000000, __CT 0.000000, __CTE 0.000000, __CT_TEXT_PLAIN 0.000000, __DKIM_ALIGNS_1 0.000000, __DKIM_ALIGNS_2 0.000000, __DQ_NEG_DOMAIN 0.000000, __DQ_NEG_HEUR 0.000000, __DQ_NEG_IP 0.000000, __FORWARDED_MSG 0.000000, __FUR_HEADER 0.000000, __FW_1LN_BOT_MSGID 0.000000, __HAS_FROM 0.000000, __HAS_MSGID 0.000000, __HAS_REFERENCES 0.000000, __HEADER_ORDER_FROM 0.000000, __IN_REP_TO 0.000000, __MAIL_CHAIN 0.000000, __MIME_BOUND_CHARSET 0.000000, __MIME_TEXT_ONLY 0.000000, __MIME_TEXT_P 0.000000, __MIME_TEXT_P1 0.000000, __MIME_VERSION 0.000000, __MOZILLA_MSGID 0.000000, __MOZILLA_USER_AGENT 0.000000, __NO_HTML_TAG_RAW 0.000000, __PHISH_SPEAR_SUBJ_SUBJECT 0.000000, __RCVD_FROM_DOMAIN 0.000000, __REFERENCES 0.000000, __SANE_MSGID 0.000000, __SCAN_D_NEG 0.000000, __SCAN_D_NEG2 0.000000, __SCAN_D_NEG_HEUR 0.000000, __SCAN_D_NEG_HEUR2 0.000000, __SINGLE_URI_TEXT 0.000000, __SUBJ_ALPHA_END 0.000000, __SUBJ_ALPHA_NEGATE 0.000000, __SUBJ_REPLY 0.000000, __TO_IN_SUBJECT 0.000000, __TO_MALFORMED_2 0.000000, __TO_NAME 0.000000, __TO_NAME_DIFF_FROM_ACC 0.000000, __TO_REAL_NAMES 0.000000, __URI_IN_BODY 0.000000, __URI_MAILTO 0.000000, __URI_NOT_IMG 0.000000, __URI_NO_PATH 0.000000, __URI_NS 0.000000, __URI_WITHOUT_PATH 0.000000, __USER_AGENT 0.000000 X-SASI-Probability: 9% X-SASI-RCODE: 200 X-SASI-Version: Antispam-Engine: 5.1.4, AntispamData: 2025.4.23.232728 X-SASI-Hits: BODYTEXTP_SIZE_3000_LESS 0.000000, BODY_ENDS_IN_URL 0.000000, BODY_SIZE_1700_1799 0.000000, BODY_SIZE_2000_LESS 0.000000, BODY_SIZE_5000_LESS 0.000000, BODY_SIZE_7000_LESS 0.000000, CTE_7BIT 0.000000, DKIM_ALIGNS 0.000000, DKIM_SIGNATURE 0.000000, HTML_00_01 0.050000, HTML_00_10 0.050000, IN_REP_TO 0.000000, KNOWN_MSGID 0.000000, LEGITIMATE_SIGNS 0.000000, MSG_THREAD 0.000000, NO_URI_HTTPS 0.000000, REFERENCES 0.000000, SENDER_NO_AUTH 0.000000, SINGLE_URI_IN_BODY 0.000000, SUSP_DH_NEG 0.000000, TO_IN_SUBJECT 0.500000, USER_AGENT 0.000000, __ANY_URI 0.000000, __BODY_NO_MAILTO 0.000000, __BOUNCE_CHALLENGE_SUBJ 0.000000, __BOUNCE_NDR_SUBJ_EXEMPT 0.000000, __COURIER_PHRASE 0.000000, __CP_URI_IN_BODY 0.000000, __CT 0.000000, __CTE 0.000000, __CT_TEXT_PLAIN 0.000000, __DKIM_ALIGNS_1 0.000000, __DKIM_ALIGNS_2 0.000000, __DQ_NEG_DOMAIN 0.000000, __DQ_NEG_HEUR 0.000000, __DQ_NEG_IP 0.000000, __FORWARDED_MSG 0.000000, __FUR_HEADER 0.000000, __FW_1LN_BOT_MSGID 0.000000, __HAS_FROM 0.000000, __HAS_MSGID 0.000000, __HAS_REFERENCES 0.000000, __HEADER_ORDER_FROM 0.000000, __IN_REP_TO 0.000000, __MAIL_CHAIN 0.000000, __MIME_BOUND_CHARSET 0.000000, __MIME_TEXT_ONLY 0.000000, __MIME_TEXT_P 0.000000, __MIME_TEXT_P1 0.000000, __MIME_VERSION 0.000000, __MOZILLA_MSGID 0.000000, __MOZILLA_USER_AGENT 0.000000, __NO_HTML_TAG_RAW 0.000000, __PHISH_SPEAR_SUBJ_SUBJECT 0.000000, __RCVD_FROM_DOMAIN 0.000000, __REFERENCES 0.000000, __SANE_MSGID 0.000000, __SCAN_D_NEG 0.000000, __SCAN_D_NEG2 0.000000, __SCAN_D_NEG_HEUR 0.000000, __SCAN_D_NEG_HEUR2 0.000000, __SINGLE_URI_TEXT 0.000000, __SUBJ_ALPHA_END 0.000000, __SUBJ_ALPHA_NEGATE 0.000000, __SUBJ_REPLY 0.000000, __TO_IN_SUBJECT 0.000000, __TO_MALFORMED_2 0.000000, __TO_NAME 0.000000, __TO_NAME_DIFF_FROM_ACC 0.000000, __TO_REAL_NAMES 0.000000, __URI_IN_BODY 0.000000, __URI_MAILTO 0.000000, __URI_NOT_IMG 0.000000, __URI_NO_PATH 0.000000, __URI_NS 0.000000, __URI_WITHOUT_PATH 0.000000, __USER_AGENT 0.000000 X-SASI-Probability: 9% X-SASI-RCODE: 200 X-SASI-Version: Antispam-Engine: 5.1.4, AntispamData: 2025.4.23.234228 DKIM-Signature: v=1; q=dns/txt; a=rsa-sha256; c=relaxed/relaxed; s=default; d=pmoylan.org; bh=VqznTeSjeRtbLf3PABqdkwc2SMqgepQu2BwGkdeCZsw=; h=From:To:Date:Message-ID; b=VvhxxFQDLc9KKolHd0doJUZvtlyOL9gCjJdavr5fxpFT7SCpTEyaZz07pdTiuPFCjlcwz muU7W1leqwEv5/5ArtFLN9gmNE2J6N7C3gDr95AgAK/q68k1dB3wxjdWSufZvBYi7o0XKev CsZAr/ArtiiLvnAgO3Js9EmHmQuVVlA= Received: from [192.168.20.3] (peter.pmoylan.org [192.168.20.3]) by mail.pmoylan.org (Weasel v3.03) for ; Thu, 24 Apr 2025 10:18:11 +1000 Subject: Re: [eCS-ISP] Trouble getting mail delivered to Office365 (outlook.com), ProofPoint, and Barracuda protected domains To: eCS ISP Mailing List References: Message-ID: <68098342.3020906@pmoylan.org> Date: Thu, 24 Apr 2025 10:18:10 +1000 User-Agent: Mozilla/5.0 (OS/2; Warp 4.5; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit On 24/04/25 03:19, Lewis G Rosenthal wrote: > > On a lark, I tightened the DKIM policy from none to reject, and added > a 50% limiter (pct=50). To avoid duplicating the DKIM header, I have > turned off the smarthost configuration, and am only sending through > the firewall local to the mail server. I was going to suggest avoiding having two DKIM headers. Although the DKIM standard does allow for this possibility, we don't know much about how well DKIM checkers handle this case. Running mailing lists is always a little risky, because some receiving servers like to reject mailing list mail. Your other mail headers look pretty safe to me, though, so I doubt that this is a problem in the present case. The big problem, I suspect, is that some big mail services might be adopting a "silently reject" policy, simply discarding mail they don't like instead of returning a failure reply. My choir uses a Yahoo mail account (against my advice), and a problem we had was that messages to all members went only to some members, and we were never notified about the failures. I'm no longer on the choir organising committee, so I don't know whether they are still doing it. Your pct=50 change applies only to incoming mail, so shouldn't be relevant. However, that reminded me of a problem with outgoing mail to multiple recipients. The SMTP standard says that every mail server must be able to handle up to 100 recipients for a single message, but I've found that some servers don't respect that and that the batch size has to be limited to 50 or even further. On the other hand I suspect that that "batch" issue only arises inside your own system, so maybe it's not a problem. -- Peter Moylan peter@pmoylan.org http://www.pmoylan.org