When trying to send email from a different address in Outlook on Office 365 you may receive Error 80070005 :
Your message did not reach some or all of the intended recipients. Subject: test Sent: 18/03/2014 14:26 The following recipient(s) cannot be reached: 'firstname.lastname@example.org' on 18/03/2014 14:26 This message could not be sent. Try sending the message again later, or contact your network administrator. Error is [0x80070005-00000000-00000000].
Quite a few people have reported that creating a new Outlook profile solves the problem but this did not work for me. I believe the cause of the issue in those instances is related to the auto-complete cache in Outlook.
Add the correct send-as permissions using Powershell to resolve Error 80070005
Even though I had already added the correct send-as permissions within the Office 365 web based administration system I decided to try adding them again within Powershell to see if this gave any different results.
After adding the permissions with Powershell I was able to send-as no problem at all and the error 80070005 ceased.
Adding send-as permissions with Powershell is easy and I have written a separate post on how to do it here