While creating account I get this error. The account is created but there’s problem creating email accounts.
Adding default mail aliases …
… Mail for domain failed! : Can’t call method “flock” on an undefined value at /usr/libexec/webmin/exim/exim-lib.pl line 257.
Please help.
Mmm, sounds like a bug with the Exim support!
While Exim support is still considered experimental, things like creating accounts should work 
My recommendation would be to file a bug report, using the Support link above, and then Jamie can take a peek at it.
Thanks!
-Eric
Exim doesnt seem to work. Postfix Mail server worked.