Please make sure you add the hostnames and URLs below to your allowed list. Your users need to be able to access these hostnames via HTTPS (port 443):
Please make sure your users are able to send/receive emails to/from:
Add the IP 18.104.22.168 to your Allowed Senders list
If you are using Microsoft Office 365 with Safe Links or a similar service that scans links in emails for malicious code, please review this FAQ article.
For more security FAQs please view our TrustPage here