Sending email using third party servers
Why email sent from other servers on your behalf can be rejected, and how to authorize those servers safely.
You can authorize third-party servers to send email on behalf of your domain. We have security measures in place to stop unauthorized servers from using your domain.
Why we do this
Spammers look for domain names and email addresses they can use as the "sender" in spam campaigns. Without the right protections, a spammer could send a mass email to hundreds of thousands of people using your email address as the sender.
Imagine all of those people seeing your company or your name on a malicious email. It could damage your brand. It can also hurt your future email delivery, because people who marked those messages as spam, or blocked your address or domain, can stop your real email from reaching them.
The 3 protections we use
1. SPF. EnGuard email routing requires this DNS record. It tells other mail servers that email from your domain must come from EnGuard servers only. A server that follows basic SPF rules will reject any email from your domain that does not come from an EnGuard server.
2. DKIM. This checks that a message is real and was not changed. It is added as a TXT DNS record for every domain that uses EnGuard for email. It tells other mail servers the email really came from its original server. It is essential by our standards, and it is also a HIPAA requirement.
3. DMARC. This is the newest tool against spam abuse. It combines the checks of both SPF and DKIM. For a message to be accepted anywhere in the world, it has to pass both.
We turn these protections on for your domain by default, whether you host your DNS with us (which we recommend) or somewhere else. If another mail server sees a message from your domain that came from an unauthorized server, it rejects the message with an SPF error or a DMARC error.
Authorizing a third-party service to send as you
Recommended: If you use a third-party application and need to authorize outside email servers to send on behalf of your domain, get the IP address and mail server names of every sending server and add them to your SPF record with the right syntax.
Not recommended: You can ask us to turn off SPF protection for your domain so you can send with third-party servers. This raises your risk of spoofing and increases your liability if someone sends malicious email as your domain. We do not advise it.
Please email our support team for help setting up your security DNS settings.