Relevant Product: Exclaimer Cloud - Signatures for G Suite
When you perform a message trace in Office 365, you notice a duplicate entry for all email messages that have had a signature appended.
This is expected behaviour when using Exclaimer Cloud.
The Office 365 Tracing tool displays an entry for the email message that is being routed from your tenancy to the Exclaimer Cloud hosted servers.
The duplicate entry is for the email message returned from Exclaimer Cloud to the Office 365 tenancy, for delivery.