SMTP Servers:
- Mail Server IP Address:
- Primary SMTP Server: 209.15.205.180
- Transactional SMTP Server: 198.21.7.99
- Reverse DNS (PTR):
- Primary SMTP Server: outbound.volunteer2mail.com
- Transactional SMTP Server: o2.trans.volunteer2mail.com
- Forward DNS (A):
- Primary SMTP Server: outbound.volunteer2mail.com
- Transactional SMTP Server: o2.trans.volunteer2mail.com
Our outbound SMTP servers:
- Standard emails are sent from: 209.15.205.180 (outbound.volunteer2mail.com)
- Transactional emails (password resets, system notifications, etc.) are sent from: 198.21.7.99 (o2.trans.volunteer2mail.com)
These servers are whitelisted and registered in feedback loops with major providers such as Hotmail, Yahoo and AOL in accordance with bulk-sending best practices. We also continuously monitor the sending reputation of these servers to ensure optimal delivery.
If possible, it is recommended that you whitelist our outbound mail servers to ensure deliverability. These are both dedicated IP addresses that are used for the sole purpose of sending mail from our application (we do not send any form of advertising or marketing mails from these servers).
We send all email using opportunistic TLS encryption, meaning it will be sent using TLS if the recipient’s email server supports it. Otherwise, it will be sent in plain text to ensure deliverability.
When we send mail through our service, the headers are as follows:
Return-Path: <bounce@volunteer2mail.com>
From: “Your Name” <you@yourdomain.com>
To: “Recipient Name” <recipient@theirdomain.com>
Under some circumstances, to ensure deliverability, we need to use the following headers to send the mail instead (note the addition of the “Reply-To” header and the use of “message@volunteer2mail.com” in the “From” header):
Return-Path: <bounce@volunteer2mail.com>
From: “Your Name” <message@volunteer2mail.com>
Reply-To: “Your Name” <you@yourdomain.com>
To: “Recipient Name” <recipient@theirdomain.com>
Reasons why this is done are as follows:
- The sender’s domain contains a DMARC (link to: https://dmarc.org/) record with a policy of either: “reject” or “quarantine”.
- We detect (via an MX lookup) that the sender’s email is being hosted in Office 365. This is done to avoid message such as “This Sender Failed Our Fraud Detection Checks and May Not Be Who They Appear to Be” from showing to your recipients.
- We detect a TXT record in the sender’s domain with the value of “_betterimpact-rewrite-sender”. Note: this can be used to force the use of a “Reply-To” header for your domain in circumstances where the “From” header would cause issues with fraud detection / spoofing in your email environment.
Typical Email Headers (for reference purposes)
Return-Path: <bounce@volunteer2mail.com>
Received: from [209.15.205.180] ([209.15.205.180:65508]
helo=outbound.volunteer2mail.com) by smtp51.gate.dfw1a.rsapps.net
(envelope-from <bounce@volunteer2mail.com>) (ecelerity 2.2.3.46 r(37554))
with ESMTP id 2F/94-09431-B184BFD4; Fri, 17 Jun 2011 08:27:07 -0400
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed;
s=s1024;d=volunteer2mail.com;
h=from:to:sender:date:subject:mime-version:content-type:message-id;
bh=wixYDQhFU6dOc6HhkA2YYmdhV0s=;
b=lapra2B3liMDpfGSzY5TNbXuPIOb8Ep+98dp8+uDLjPmZxElgAo4o5IvdsDbBXfdsLKIMoHf
bHFKiFmugrV/DnRlTi4RMOK3l+xvtPR8dfrXqcnERQdOKSDNaU6XUnqRFEDj0xNg8s5DsnAW
WGnVAETTXAYtaraReENUgITtWtY=
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws;
s=s1024;d=volunteer2mail.com;
h=from:to:sender:date:subject:mime-version:content-type:message-id;
b=GGLkdKj1hCa8HE8MS0WLcOONj3IzyfwP7cm8uAbNa1OU762gusqtHlNHI4/XleIv1fwqn2vU
XoGJa/ElYw691XsDYTlPoyJ0nhnS24CwP6MNa8tUtJQmXmaoEx8+FWRpv3nxfgZK4FFshpF3
73tj2e15C8Nk04d3jnMO6ieq5eQ=
Received: from mail pickup service by outbound.volunteer2mail.com with Microsoft SMTPSVC;
Fri, 17 Jun 2011 08:27:06 -0400
From: <johndoe@example.com>
To: <janedoe@example.com>
Date: Fri, 17 Jun 2011 08:24:46 -0400
Subject: Subject
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary=”_=aspNetEmail=_d6ef38fc43584694bd897c3367f0c448″
X-Mailer: aspNetEmail ver 3.7.0.10
Message-ID: <vol2web1697b83fd01bc4e819c576c84dfeccf4e@vol2web1>
Contacting Support
If you encounter a bounce message containing information related to spamming, blacklisting, etc. (or other problems you are unable to solve directly), please contact us.