We have a shared mailbox on Exchange 2010 that multiple clients access using Outlook 2010. There are multiple distribution lists (that each have multiple email addresses) that point to this single shared mailbox. This was done to enable server-side processing rules to place messages into specific sub-folders depending on the email address that the message was sent to. For a (slightly) more visual example…
Email sent to vendor1@domain.com (Vendor 1 Distro) -> Shared Mailbox -> "Vendor 1 Folder"
At the moment, if a user clicks Reply, the From address is sharedmailbox@domain.com. The user can manually change this to vendor1@domain.com and it will send without issue (Send-As granted ). What I would like is for the From address to automatically default to the email address that the message was originally sent to. Is this possible without some custom Outlook extension?
Best Answer
You could implement a TransportAgent that would act as a sink for all outgoing messages that could modify the "From" email address before it is actually sent out to the recipient mail server. This would allow you to create static (or configurable if you wanted to maybe have the rules be data-driven) business rules based on message metadata. I think you might be interested in a RoutingAgent. There is some fundamental information on the SDK available here and an example here that you should be able