Couldn’t convert value : [email protected] into a valid com.company.project.domain.package.SomeClass

It looks like are just sending the class name as a String.

[email protected]

This is the default toString() implementation on Object.

i.e. SomeClass.getName() instead of someClass.getName() (assuming there is a getName() method on the class.

EDIT

I didn’t notice it was a header, sorry.

The message converter only performs conversion on the payload.

For headers, you need to implement a custom HeaderMapper – Spring just passes headers to the amqp-client, which does a toString() on types it doesn’t know.

Subclass the DefaultAmqpHeaderMapper and override populateUserDefinedHeader on the outbound side and extractUserDefinedHeaders on the inbound side.