Good day,
All the mails will need to be deleted from the mailbox and then you can proceed to close the mailbox.
The link below describes how you can delete all the mails from the mailbox:
http://www.hansamanuals.com/main/manuals/mailnumber___462/theconf___86/hwconvindex.htm
Once the mails have been deleted, to close the mailbox you should navigate to:
Email and Conferences >> Registers >> > Highlight the mailbox you would like to delete >> Properties >> Select the Closed Checkbox.
It is very important to ensure that all the mail is deleted from the mailbox before closing it.
With regard to the StandardID, it depends on the Standard ERP version that you are using. In older versions, when you enter an email address on the persons card, this will be their StandardID. In newer versions of Standard ERP, on the person card, their is a field for the users StandardID (email address). In both cases, the StandardID has to be verified. The user will receive a mail to their mailbox with a link that they have to select.
You can also create a new StandardID using the MyStandard page:
https://mystandard.hansaworld.com/loginpage
Kind Regards,
Tayla Anniciello