This is a configuration mistake, the domain name is being used in two places for two different things.
Domino Administrator -> Configuration Tab.
-> Servers
---> In the Server document the "Domain name" is entered "Acme", this is correct.
Domino Administrator -> Configuration Tab.
-> Messaging
--> Domains
---> Global Domain
-----> The entry "Global domain name" cannot be the "Domain name","Acme", this confuses the server, use "Domain name + internet or SMTP", for example "Acme internet".
Sincerely
Douglas Bryant
email@dbryant.de
www.dbryant.de