as a work around, first create it as a mailbox and then disable the mailbox and enable the mail alias.

As far as I know Parallels changed how this worked in one of the patches. They removed aliases with a dot because of a bug in vpopmail. So instead of upgrading vpopmail they blocked aliases with dot.

vi /hsphere/local/home/cpanel/shiva/shiva-templates/common/submit/email/s_email.yafv

change:
regexp vMAliasName= "\w+[\w\!\#\$\*\+\-\=\?\^\~]*([\w\!\#\$\*\+\-\=\?\~]+)*", maxlength="128", fail=yafv.vMAliasName.fail;
to:
regexp vMAliasName= "\w+[\w\!\#\$\*\+\-\=\?\^\.\~]*([\w\!\#\$\*\+\-\=\?\~]+)*", maxlength="128", fail=yafv.vMAliasName.fail;

save and exit.
login to cpanel user
su - cpanel
cd shiva/shiva-templates
.configure
make

exit cpanel user
restart control panel
service httpdcp restart

aliases with dot will now work. Though I can't be responsible if qmail bug pops up with why parallels disabled it in the first place

Further on the topic is here, and talks about further code that would need to be done by the backend of Hsphere to convert . (dot) to a : (colon) for aliases in qmail.
http://www.forum.psoft.net/showthrea...ight=alias+dot

Filed as TP#46775