Issue: This message could not be sent. Try again later or contact your network administrator. Error [0x80004005-000000000-00000000]
Scenario: Organization has throttling policy with recipient rate limit of 10,000 per day set for the organization. For this org, service mailboxes aren’t throttled. User has 2 mailboxes (primary and service mailbox) opened in Outlook. User has send-as permissions to the service mailbox but as a group member.
User tries to send from outlook as service mailbox to multiple recipients but received error message. see error message below
Undeliverable: your message did not reach some or all of the intended recipients. This message could not be sent. Try sending message again later or contact your network administrator. Error is
[0x80004005-000000000-00000000].
Resolution: Advised user to send message using Outlook web Access. User needs to login to OWA and open the service mailbox. Messages can now be sent without throttling.
Alternatively, for a user that insist on using Outlook, user must be given explicit send-as permission to the service mailbox so as to be able to bypass throttling policy
Ex-Shell 