If ever an SPF (Sender Policy Framework) failure occurs, messages routed from Exclaimer Cloud - Signatures for Office 365 may get marked as spam. To ensure this does not happen, you need to add an include mechanism for 'spf.de.exclaimer.net' within your SPF record.
If you're not familiar with what an SPF record is, it decides whether a mail server or cloud-based email service like Office 365 is allowed to send out email from your domain. For example, if your company had the domain 'greenorg.net', your SPF record would confirm that Office 365 can send any emails ending with '@greenorg.net'. As your organization is currently using Office 365, you should already have an include mechanism for Microsoft's 'spf.protection.outlook.de' domain.
With this in mind, you need to add 'spf.de.exclaimer.net' to your SPF record as the message header on all emails will indicate they passed through Exclaimer Cloud. If the recipient's email server checks the message against your SPF record and finds that Exclaimer isn't included, your email message may get rejected.
Put simply, it means that by including 'spf.de.exclaimer.net', you ensure, whatever your SPF softfail or hardfail settings are, email will always be sent as normal.
All you need to do is add the below line to your SPF record:
If you aren't sure where this line goes within your SPF record, we recommend placing it directly after the include mechanism for outlook.com, as that will already be in the right place for sending email. At the very least, make sure the line appears before the 'all' mechanism as that is effectively the end of the SPF record.
v=spf1 mx ip4:18.104.22.168 include:spf.protection.outlook.de include:spf.de.exclaimer.net ~all
There are many hosting providers available and each one may have a different method for editing your SPF record as it is a part of your DNS settings. If you do not know how to access your SPF record, we recommend that you either contact your hosting service provider or whoever is responsible for hosting within your organization.