SPF identifies which mail servers for a domain are allowed to deliver emails. If a receiving server successfully checks an SPF record, the sending server is authenticated. It's sent as spam if SPF doesn't check it out. You must add an SPF record for Help Scout in order to identify it as an approved email sending source for your domain.
Creating an SPF Record for Help Scout
Here are the steps to set up SPF for Help Scout :
Login to your DNS management console
Navigate to Tools & Settings > DNS Template
You need to edit the DNS TXT record related to SPF
An SPF TXT record for Help Scout will have the following syntax:
mydomain.com TXT v=spf1 v=spf1 include:helpscoutemail.com ~all
Publish this record in your DNS records section for your respective domain.
Note: If you don’t have an SPF record previously for your domain, simply publish the above-mentioned record to enable SPF for outgoing emails using Help Scout. If you do have an existing SPF record in your DNS, you need to modify it to include Help Scout, as shown below:
Previous SPF record: v=spf1 mx -all
Modified SPF record: v=spf1 mx include:helpscoutemail.com ~all
Wait for 72 hours to allow your DNS to process the changes