Hello guys,
i've never used Let's Encrypt for securing mail server so i need some help:
my email domain (let's say domain.com) differs from server's hostname (let's say server.hostname.com), so i was wondering if i should obtain certificate for domain.com or for server.hostname.com? I'm not sure because my first thinking was to obtain certificate for domain.com, but when i look at email headers:
Delivered-To: example@gmail.com
Received: by 2002:ab0:2098:0:0:0:0:0 with SMTP id r24csp2306985uak;
Tue, 24 Mar 2020 11:09:43 -0700 (PDT)
X-Google-Smtp-Source: ADFU+vuCOcG14riCFITKQMWQLHsRftw292QjMrLaAWQS0V+SOhLmyEnJkt2uJpP+aO7MMbu/vDpo
X-Received: by 2002:a50:eb05:: with SMTP id y5mr28431049edp.168.1585073382877;
Tue, 24 Mar 2020 11:09:42 -0700 (PDT)
ARC-Seal: i=1; a=rsa-sha256; t=1585073382; cv=none;
d=google.com; s=arc-20160816;
b=YI9gLpG97INXX/dvhPKZjQL3jODq5L2XNgCgAe2GVKx67faWrRKD2AmD/Y2qxAru9G
rLa07kvXMYtCqjyBipxOpjhwdzbJVDSgE1bFLjdNNB2U7jhHplOqaRzMTKpc1eMpTFKj
KaXvWWALOpPsU+RiFInn7e89VKIQuSkbGCiwMO7urQyF9H9QDCPNO6y2Pw97sJe5GzXV
ErwkUNJRtwFuCU2b1RR+tlUp0S5XDcRiJy/S87KElzcKHBZ2SbYxEc4cyJcaPpTwpVps
qgV1+tGCGDjm4+SV+xkP9z9qSQLzj6eUMmF1QQWqW71493WZJ37xmibE908Yy/eSKMZw
2ztQ==
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816;
h=to:mime-version:subject:references:in-reply-to:message-id:from:date
:dkim-signature:dkim-signature;
bh=ViCYMe/4JFrFOOqUu8R1lbCBQLUtiXbXFcNA1cMFVWA=;
b=btOGXLlSds/VKOe7Q/E+KT6KMWFUBs90qBGBW/cwNJsIaChFakrJ+FFeM3JNK7WhYy
44B/56AnsOXBtJuA4fUeEuPJLcxHu5HY5SFaY8esdHg7tL/UfMu8S9Q0RQfz6REYu8Fs
jroR6ymMqdvu9TXnkCFmG2YAz+04GzxKDyQVW3d9t/G8pT7y2/qAVIrm2MIxHDJ3xSFc
MEfaKeItet8H6/31JxcAb2WIxQ2lFtW16m3gPmXtwN7vMPNhUQwJV5Y1xPlRAT+KHKwB
YjuuwOernorvdt4uKmurtJKHp7HtbWQksh6CSlkESE8pT0GwVtOVb2oqAUZgfuFxhD0h
NVxg==
ARC-Authentication-Results: i=1; mx.google.com;
dkim=pass header.i=@domain.com header.s=s1 header.b=gfvcJGPa;
dkim=pass header.i=@sendgrid.info header.s=smtpapi header.b=PcSDz8NZ;
spf=pass (google.com: domain of bounces+2967257-b81e-example=gmail.com@email.domain.com designates 198.21.6.101 as permitted sender) smtp.mailfrom="bounces+2967257-b81e-example=gmail.com@email.domain.com"
Return-Path: bounces+2967257-b81e-example=gmail.com@email.domain.com
Received: from cskrhssr.outbound-mail.sendgrid.net (cskrhssr.outbound-mail.sendgrid.net. [198.21.6.101])
by mx.google.com with ESMTPS id v27si6584120edd.354.2020.03.24.11.09.41
for example@gmail.com
(version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128);
Tue, 24 Mar 2020 11:09:42 -0700 (PDT)
Received-SPF: pass (google.com: domain of bounces+2967257-b81e-example=gmail.com@email.domain.com designates 198.21.6.101 as permitted sender) client-ip=198.21.6.101;
Authentication-Results: mx.google.com;
dkim=pass header.i=@domain.com header.s=s1 header.b=gfvcJGPa;
dkim=pass header.i=@sendgrid.info header.s=smtpapi header.b=PcSDz8NZ;
spf=pass (google.com: domain of bounces+2967257-b81e-example=gmail.com@email.domain.com designates 198.21.6.101 as permitted sender) smtp.mailfrom="bounces+2967257-b81e-example=gmail.com@email.domain.com"
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=domain.com; h=from:in-reply-to:references:subject:mime-version:x-feedback-id:to: content-type; s=s1; bh=ViCYMe/4JFrFOOqUu8R1lbCBQLUtiXbXFcNA1cMFVWA=; b=gfvcJGPaGjgt0D0jeYfkXZzzV5Rat+u8DK4offLfgj/AIuCzjlTR5lofpoWQi2BxM8iw MuMyrdNxWVt67mBZuXQ9otnSxXWw+200ysHnA30TUdmZaNnuASmkO7tN+7kLYpcLAiM9Nd CKxAAbqmIYkBBJOEEigfkNg70Jdim8Kng=
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sendgrid.info; h=from:in-reply-to:references:subject:mime-version:x-feedback-id:to: content-type; s=smtpapi; bh=ViCYMe/4JFrFOOqUu8R1lbCBQLUtiXbXFcNA1cMFVWA=; b=PcSDz8NZbE1xDEax7yQNViFnf5SB2cc9LvewHLJwQxTm5xqhZmicCv4fL02zjaoTvlyh X49lrVZLbFCICjIIXdTsMDpbzErcPtjX6nJ2b0gH9h3gnSo09EtHW4pHnyHXfcWGzqwlsZ OQRNy0Cra9I8lZiI3ky/oJtcjwSEazbe0=
Received: by filterdrecv-p3las1-648dcbd4bf-mwnx5 with SMTP id filterdrecv-p3las1-648dcbd4bf-mwnx5-20-5E7A4CE3-6F
2020-03-24 18:09:39.883730297 +0000 UTC m=+687330.469828445
Received: from server.hostname.com (unknown) by ismtpd0001p1lon1.sendgrid.net (SG) with ESMTP id p3kpZjTvSAynai1xGrj-Jw for example@gmail.com; Tue, 24 Mar 2020 18:09:39.501 +0000 (UTC)
Received: from [192.168.1.156] (cable-89-216-20-83.cable_provider_isp.tld [89.216.20.83]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by server.hostname.com (Postfix) with ESMTPSA id 9BE2B5C597 for example@gmail.com; Tue, 24 Mar 2020 19:09:38 +0100 (CET)
Date: Tue, 24 Mar 2020 18:09:39 +0000 (UTC)
From: adam@domain.com
Message-ID: 86a27dea-9bba-4b01-a18c-46198a501382@Spark
In-Reply-To: bd3c27d5-9ae4-495a-875d-936bcff1b20f@Spark
References: cc326246-b383-4829-aac2-a0cea1af70be@Spark bd3c27d5-9ae4-495a-875d-936bcff1b20f@Spark
Subject: Fwd: Sastanak u 10
X-Readdle-Message-ID: 86a27dea-9bba-4b01-a18c-46198a501382@Spark
MIME-Version: 1.0
X-Feedback-ID: 2967257:SG
X-SG-EID: 9gxTU0Q2NoXm3y/gNIc6GG1xB0HYfq9dA5dPJe/6vb2j9cCOQLWEYCWdyoUihC3P4Fn5ChGM5dze95PAKibu5LxQtorv4p81s7B7xd8++wKWVzgo8QLN4W+Q1XfarvQP1yAhGVf5XXZvJi1OVB3BPR13W7G2jh26Lr9s7QeM01wFW64X2db3o6+wQz/zI09mwtzag0wIycj5C8OiGj1irmSKo6GZoFTUF8HPTQAxWAU=
To: User example@gmail.com
Content-Type: multipart/alternative; boundary="5e7a4ce1_6b8b4567_26c"--5e7a4ce1_6b8b4567_26c
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline
it says that it has been received from server.hostname.com so maybe i should obtain certificate for server.hostname.com instead?
Maybe i should emphasize that i'm using SendGrid as SMTP relay.
Thanks in advance!
