Send from secondary E-Mail-Address in Echange 2013 / Outlook 2013

We are running an Exchange 2013 Server with Outlook 2013 as Clients.

On some accounts we need multiple E-Mail-Addresses. We configured them in ECP and gave the users Send as and Full Access permissions for their Mailbox, just in case.

They receive E-Mails on these addresses, however, we want them to be able to send from them.

Now here's the thing:

• When they send from a secondary address in OWA, everything's working fine
• When they try to do the same in Outlook, they get a permissions Error (0x80070005-0x0004dc-0x000524)

We already waited long enough, just in case it had to do with replication.

Any ideas?

Can you explain exactly that you did? Have you created additional mailboxes, or just added the addresses to the existing mailbox? It should like the former, but if it is the latter, then that doesn't work.

If the former, how are you selecting the address to send as within Outlook? Entering the email address in the from line rarely works - similarly neither does using a nicknames entry. Selecting from the GAL is the best option. If you are using Outlook 2010 or higher, adding the adding mailboxes as an additional ACCOUNT within Outlook will give you an easy drop down list for the From field.