"Could not create user" error in SmarterMail

Due to a limitation in the way Windows operates, some usernames are not permitted in SmarterMail. These are:

con
aux
com1
com2
com3
com4
lpt1
lpt2
lpt3
prn
nul

Note that this limitation also applies to usernames with a period following the reserved word, such as; nul.name@yourdomain.com.

So, for example, these usernames will fail to be created:

nul@yourdomain.com
nul.name@yourdomain.com

And these will be created successfully:
nul-name@yourdomain.com
nulname@yourdomain.com