The Editor role has access to wordpress admin because he can publish posts etc.
I tried to do it from Acymailing -> Configuration -> Security -> Advanced configuration -> Permissions -> “Allow these user groups to access AcyMailing?“
In this select field there is no option for administrator which i guess is enabled by default. I chose there “editor”. But when the editor goes also into configuration to change for example the Mail settings -> From name etc and clicks save, this setting i chose above gets overwritten, and then he cant access acymailing at all.