Notes/Domino 6 and 7 Forum : Internet alias and local part not working

Has anyone had similar problems since upgrading to R6.

We upgraded from R5.0.11 Domino to R6.0.2 CF2 Domino and found the following problems: It is an SMTP and Mail Server.

1. Mail being received from the Internet previously would resolve to an internal internet name with a full stop or underscore eg. joe_blogg@..... or joe.blogg@...
Now it doesn't. We have since upgraded to R6.5 and still have the same issue. We have added the following configuration setting but it made no difference.
SMTPMTA_SPACE_REPL_CHAR=.

2. The second issue since the upgrade is that we have to change the Address Lookup in the Configuration Document to Local Part in order for internet alias and Username alias to work.
eg. Joe Smith
Smithy (won't work)
joe_smith@server1.com.au
joe_smith@server2.com (won't work)
All domain documents, connection documents are all configured correctly and work fine before upgrading.

3. To sum up the problems:

Using Domino 6.0.2CF2 server fullname & Local Part does not resolve internet & username alias settings (need to have local part only). Does not resolve a full stop and underscore.

Using Domino 6.5 server and Domino Directory template 6.0.2CF2 the issue is the same as above.

Using Domino 6.5 server and domino Directory template 6.5. The setting Local part doesn't work at all to send any mail. Full name & local part sends mail to Username and Internet address specified but no aliases. Full stop doesn't work.

Any assistance would be helpful please.

Thanks in Advance.