Checked for the Helpdesk user
ah, now we may be getting somewhere, is that for the test account to?
mmh, just yours is unticked right? If you check thr send-as permission via the EMC for helpdesk, does it clearly show the name or does it show guid?
The very 1st time you send the email via Outlook it works and any attempts after fail & it always works via OWA? just read the post again & want to make sure it clear? You also mention ABP, how are they configured? Any chance to have a look at this over a webex or something similar?
What's your day job? Lol
address book policies. Day job, urrm, im learning exch, lol, iman exch admin -:)
from OWA, did you not choose the From Field to send as?
Outlook Web App (OWA) for Exchange 2010 has the From field option
For your email address policy, you defo have all 3 smtp domains defined?
And you are 100% sure the the default SMTP address is domain3 and that is what you're trying to out as. It seems like send-as is not working at all. Open another mailbox is different as we have seen it fails in owa too using thr from field.
can you run get-mailbox "helpdesk alias"| fl
domain1 for anything. It's just a receiving address.
Can try the powershell command tomorrow. Is the alias the alias in the properties?