You can now use a dot in the email alias. We are working on providing the ability to edit the email address of a group after creation.
For the ability to edit the email addresses, we now have the following roadmap item: https://products.office.com/en-US/business/office-365-roadmap?filters=&freeformsearch=27891&featureid=27891
An error occurred while saving the commentNigel Gibbons commented
Further to my last post a quick update.
Instead of relying on the generic 'Get-Recipient' command I found the emails associated with the O365 Groups using:
'Get-UnifiedGroup -ResultSize Unlimited | select DisplayName,RecipientType,EmailAddresses | Out-GridView'
Thanks to Adam Drayer (http://online.platformscholar.com) for pointing this out to me.
This does not excuse the lack of visibility of these O365 secondary emails in the console or external routing that I still cannot get to work on the secondary aliases. Furthermore the fact that O365 Groups also seems to create additional undisclosed emails.