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Upcoming Greenhouse Recruiting Email Changes

Email is the highest-volume and most critically important way to keep in touch with candidates, prospects, and even your own employees during the recruiting process! That’s why we’ve dedicated significant engineering resources over the past few months to strengthen our email infrastructure so your messages have the best possible chance of reaching their recipients. The purpose of this blog post is to provide a head’s up about some upcoming changes so you aren’t caught off guard.

  • Who does this post apply to?
  • Unverified Domain Warnings
  • Broader Bounce-Back Emails
  • Additional IP Addresses
  • New SPF Record Option
  • Questions or concerns? 

Who does this post apply to?

A majority of Greenhouse customers rely on our internal systems to send email and will be impacted by these changes, but there is one exception. If your company has configured a custom SMTP server to manage all of your Greenhouse email, the changes in this post will not impact your email behavior. If you’re not sure whether this applies to your organization, have a Site Admin navigate to the Configure > Email Settings page and click on Show verification details. If the verification details provide information on an SMTP server (see below for an example), then this post does not apply to you.


If they don’t see the words “SMTP server” anywhere, then read on. It’s time to talk about those upcoming changes...

Unverified Domain Warnings

The single most important way to help ensure your messages are delivered is by verifying your domain with Greenhouse. When Greenhouse sends a message from [email protected], it doesn’t actually send from your email account! Instead, it sends the email from Greenhouse’s third-party email tool and just sets the from address to be the user’s email.

This is a super handy feature, but if not configured correctly, it could also appear as if Greenhouse is doing something sketchy and impersonating your email without permission, leading to many of these messages being flagged as suspicious. By verifying your domain (click here for instructions), you’re explicitly granting Greenhouse permission to send on your behalf and telling the recipient’s email client that Greenhouse is a trusted sender for your message.

Very soon, any time you attempt to send a candidate email or rejection email from an unverified domain, we’ll surface this warning to let you know that the message may be flagged as suspicious.


Perhaps your domain was verified but became unverified because of actions taken by your IT team. Maybe it seemed verified, but was set up incorrectly and has been in danger of failing for quite some time. Or maybe this step of the setup process just got skipped altogether! Whatever the reason, this message should alert Job and Site Admins of a potential problem so your IT team can work on getting it fixed.

Broader Bounce-Back Emails

When users send email through Greenhouse Recruiting that can’t be delivered, we will sometimes provide a bounce-back message to let them know that something went wrong. As part of our investigation, however, we realized that there are hundreds of additional failed emails that we haven’t been notifying users about, so we’re going to start doing that!

Over 90% of the failures are caused by typos, either in the candidate’s address (like [email protected]) or in the domain (like [email protected]). We’ll be able to surface the specific problem back to the user who sent them email so they can fix any errors and try again. A much smaller number of errors are caused by the message appearing too spammy for the recipient’s email provider to accept. Of these, some could be caused by missing or improper email verification, while others might be caused by a previously-rejected message or language in the email that sounds spammy:


No matter the reason, we hope that providing more insight into when and why an email fails will help your team correct any issues so your recipients aren’t left wondering why they didn’t hear from you.

Additional IP Addresses

For many of Greenhouse’s customers, we send our customer emails through a third-party email provider called Mailgun. We used to have only two IP addresses dedicated to our account in Mailgun, which meant that all customer email sent through those two IPs. As part of the initiative to improve email deliverability, we’ve increased our list of dedicated IPs to a total of eight IP addresses in Mailgun. This means that we’ll be sending significantly less traffic through each IP address, which should improve the chances that your email will be accepted and not marked as suspicious.

Some customers may have had their IT teams whitelist our original two IP addresses to ensure that email to their internal users delivered successfully. If your company has whitelisted our original IP addresses, please update your IP address whitelist to include our new IPs. Even if you’ve never whitelisted our IP addresses, we still recommend that your IT team whitelist our IPs to ensure that emails to your users arrive successfully and don’t get caught up in the Spam folder. The complete list of IP addresses to whitelist is:


If whitelisting IPs is important for your organization, please make sure these additional options by December 1st, 2017.

New SPF Record Option

As part of verifying your domain, your IT team will need to add an SPF record to your domain’s DNS settings. Up until recently, Greenhouse recommended adding the general Mailgun SPF record: “v=spf1 ~all”.

Adding this SPF record is one step in granting Greenhouse permission to send email from your users, but some customers found that the record was a bit too broad, as it incorporates a large number of IP addresses from Mailgun and adds a hefty three DNS Lookups to the SPF record for the domain. We’ve recently created a lighter SPF record option, which will only include Greenhouse’s dedicated IP addresses in Mailgun and will only add one DNS Lookup to the SPF record for the domain. The new SPF record option, now visible on your Email Settings page, is:

“v=spf1 ~all”

This will be great news for your IT team for practical and security reasons, as adding our new SPF record will mean you’ll have more room to add other records to your domain and can completely restrict access to only the Greenhouse dedicated IP addresses!

Questions or concerns?

We’ve packed a lot of information into this post, so we expect you may have questions. Feel free to browse our email support articles or reach out to your account manager or [email protected] with any questions or concerns and our team will be happy to assist you!