Recently I got questioned which parameters or settings are responsible whether a group, entered into one of the three address fields of an email message (to; cc or bcc), will be expanded or not.
There are of course some rules around this and while some of them do not seem to be related at all, there is some logic when the facts described below are combined.
If a group is stored in a local directory (address book) the group will be expanded by the Notes prior to sending out the message. The same happens when the fields on the document are refreshed (F9-key). Is the group stored on a server-based directory (e.g. the Domino Directory or Directory Catalog) the group will be expanded by the mail router on the server but not the client.
Therefore a group which had been created by the user in her/his local address book will expand whereas a group created by the administrator in the Domino Directory keeps unexpanded.
A (local) replica copy of the Domino Directory configured as an additional address book in the mail preferences does behave similar to any local address book and will therefore expand groups as well.
When sending a message, local address books are always validated first. The group name will be looked up in all local directories before the search for the (group) name continues on any server based directory.
If the ‘Recipient name lookup’ setting in the current location document is set to ‘Stop after first match’, Notes uses the first matching entry and expands it, if it has been found on local. This is the case when Domino Directory based groups are expanded on the Lotus Notes client even you would consider otherwise.
If however the ‘Recipient name lookup’ setting in the current location document is set to ‘Exhaustively check all address books’. Notes tries to find the group in all possible directories (local as well as on the server). Since the group will be found on the server replica of the Domino Directory as well the individual members of the group will not be extracted.