smells a bit as if greylisting would have been deployed for 'rqc.ru'. You may be right, but why? It all happens still well within RIPE:
Received: from worker1.atlas.ripe.net ([193.0.19.216]) by mahimahi.ripe.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from <no-reply@ripe.net>) id 1dhueG-0001AI-Sl for redacted@rqc.ru; Wed, 16 Aug 2017 11:30:02 +0200 Received: from [127.0.0.1] (helo=worker1.atlas.ripe.net) by worker1.atlas.ripe.net with esmtp (Exim 4.89) (envelope-from <no-reply@ripe.net>) id 1dhueG-0003zF-Qf for redacted@rqc.ru; Wed, 16 Aug 2017 09:30:00 +0000 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Probe 26656 is disconnected (RQC Ural bld.) From: RIPE Atlas (no reply) <no-reply@ripe.net> To: redacted@rqc.ru Reply-To: RIPE Atlas (no reply) <no-reply@ripe.net> Date: Wed, 16 Aug 2017 09:30:00 -0000 Message-ID: <20170816093000.18245.96974@worker1.atlas.ripe.net> X-ACL-Warn: Delaying message X-RIPE-Spam-Level: ---- X-RIPE-Spam-Report: Spam Total Points: -4.0 points pts rule name description ---- ---------------------- ------------------------------------ -7.5 ALL_TRUSTED Passed through trusted hosts only via SMTP 3.5 DCC_CHECK Detected as bulk mail by DCC (dcc-servers.net) X-RIPE-Signature: b7d297f3462a5391c8f90e217ab85ce69eb69a6fc89c21df31133e5b7354304c
Dear Marat Khalili,
Your probe 26656 has been disconnected from the RIPE Atlas infrastructure since 2017-08-16 08:58:54 UTC. [...] My provider did not treat it as spam and delivered almost instantly after receiving from RIPE.
-- With Best Regards, Marat Khalili