I have enabled that usernames are allowed during registration but I noticed a member got registered using email id.
This question doesn't make any sense for me - where exactly did you "enable that usernames are allowed during registration"? I don't recall such option in standard MyBB.
I think you have Allowed Login Methods settings with something else.
You could try an edit to the registration page by adding jquery that disallows emails in the username field. Be warned: it's kind of a band-aide fix.
may be related to disallowed usernames (admin panel >> configuration >> banning >> Disallowed Usernames)
thread starters should post clear details of the issues / requirements so that someone
will be able to respond with the possible solutions without wasting time and resources
Sorry my mistake.
Is there a way for stopping users to choose email id as their username?
try to add this *@*.* as a Disallowed Username
(2015-02-15, 07:08 PM).m. Wrote: [ -> ]admin panel >> configuration >> banning >> Disallowed Usernames
You can disallow emails by putting a filter on @gmail.com, @live.com etc.