why exim4 shows me the internal gateway in ehlo helo ?

[noise]

Hi

mail are going in and out but if i connecting over telnet
it say me: 250-example.domain.com Hello _gateway [xxx.xxx.xxx.xxx]

any ideas to hide ?

running on ubuntu 18.04.1

another thing is:
ssl letsencrypt is active but i can't save the settings. After klicking save he going always back to the Server Hostname profile.