We are setting up a new production environment which utilizes the new Sitecore Email Cloud (Sparkpost and EXM 3.4). Our hosting vendor does not allow us to open for all traffic on port 587, so we need a hostname and/or an IP range to open. I have crawled the document but have only found this statement in doc.sitecore.net:
- Make sure the firewall on your server does not block the following URL's:
- Open port 587 to support the Transport Layer Security (TLS). TLS is required by Sitecore MTA to send email messages.
From the above it seems that I need to open up for all traffic to port 587, not only for the specific 4 URLs.