These values depend on what environment your digital workplace resides in. If you are unsure what environment your digital workplace resides in, or notifications continue to not be received after whitelisting, please contact Igloo Support.
Whitelist these IPs on your organization's mail server to ensure that emails from your digital workplace don't get blocked. MX and SPF records may need to be added to the appropriate DNS. The MX record is used for emails into your digital workplace and you should only need to apply the MX record if you are not using a CNAME for your digital workplace's domain. The SPF record corresponds to emails out of your digital workplace and should be added to the domain that your workplace's emails are coming from. If your workplace's emails are originating from igloocommunites (the default), you do not need to do anything regarding the SPF record.
Also, consider adding your workplace's email domain to your organization's email client's safe sender list (Outlook | G Suite) to avoid the email client sending emails to a junk folder. Contact your organization's IT administrator about applying these settings.