Just had this discussion a while ago on linkedin in the group "Lotus Notes/Domino Technologies (7.000+ members)"

The preferred way is use the DominoTeam Mailbox from openntf.

Other options are:

http://www-10.lotus.com/ldd/ddwiki.nsf/dx/Sending_an_email_with_a_custom_%E2%80%9Csender%E2%80%9D_via_MIME

Or Steve's option:

Steve Knight • As part of an automatic database creation system for helpdesk I wrote for one customer it would request basic information then go away and create all their standard ACL groups, the database, replicas on different servers etc. and send the relevant users details of it and the groups they could administer. When needed for replying to a mail-in we just set the mail file owner as part of this LotusScript creation code, then sending a mail from within that database works in the same way as sending from someone else's mail file, i.e. From (real name) and Reply-To (the database) show.

Dim calprofile As notesdocument
Set calprofile=dbNew.GetProfileDocument( "calendarprofile")
calprofile.Owner=uidoc.fieldgettext("mailindbname")
Call calprofile.computewithform(False,False)
Call calprofile.save(False,False)
Set calprofile=Nothing

Maybe this helps?

The best way to make the address look like it is coming from the mail-in database is to deposit it directly into mail.box. That is (IIRC) what the Domino Team Mailbox is doing...

Back in 2011, I posted a class on my blog that helps in sending mail notification. In it, I use the mail.box trick to set the sender if you set the principal property.

http://blog.texasswede.com/lotusscript-mail-notification-class/

That should be easy to add to your database.

Hi,

i create the name of the mailin database hierachical. So my mailin document is named xyz/DominoOrg (the field is multivalue, you can add the old name on second place), now i can use the mailin doc as mailfile owner. I set the smtp mailaddress in the mailin doc too, so answers from this database have the sender address of the mailin db.

Regards

Chris