Since the Freshservice emails originate outside our email estate, we mark the email as "External Email", which was earlier done to reduce phishing. Since the Freshservice email is a legit email, we want to whitelist this source so the banner does not show up. We notice that the emails originate from 126.96.36.199 and the whois on this gives us o1.email.freshservice.com. One option is to whitelist the IP, however this would break when the IP changes.
I'm looking for something more concrete rather than IP maybe a hostname which may stay more stable.
Any ideas the hostname that we could use to whitelist ?
You can create spf record for email.freshservice.com which should solve this.
This article should help you out.
@Mirlos, you could also have FS send emails from your mail server with a dedicated account. That should resolve the challenge as well. I actually found this to be a better method.