when reply to mailing, mailaddress is not correct

[vantuykom]

When I send a mailing and I want to reply to it, the reply-to address is something random in stead of the email I specify...
What is this and how can I fix this?

regards

Code: [Select]

Delivery to the following recipient failed permanently:

     r.15.8595.7adbcce5c12bb69c@nacozo.be

Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the server for the recipient domain nacozo.be by mail.nacozo.be. [84.246.4.155].

The error that the other server returned was:
550 <r.15.8595.7adbcce5c12bb69c@nacozo.be> No such user here