linux pop3 user login in format <forename>.<surname>

[starms]

Hello,

I was wondering if it is possible to setup a linux account to allow a login in the format <forename>.<surname> such as 'joe.bloggs'. When trying to setup a username

$useradd joe.bloggs

it flags an error, stating that this username is invalid. Is there a way that I can allow a pop3 login in this format. I've tried adding information to /etc/mail/aliases and /etc/mail/virtusertable

i.e.
virtusertable
joeb@test.com joe.bloggs

aliases
joe.bloggs: joe-bloggs

but that does not seem to work. Am I going about this the wrong way?

Best Regards,

Mark Starmer

[falko]

Linux doesn't allow dots in usernames.