Relevant Products: Exclaimer Cloud - Signatures for Office 365
The Exclaimer Cloud service addresses a number of IP addresses. If you use third party anti-spam or virus vendors such as MimeCast (or other smart hosts), you may need to white-list these addresses. This ensures that the third-party vendor accepts the SMTP connection from Exclaimer Cloud, instead of rejecting it (which can result in a message delivery failure).
IP addresses used by Exclaimer Cloud