We have been made aware that some users that have been moved to Office 365 using Mac mail and are connected to a Hub 3 are having a problem sending mail. If you are having this problem on most cases this can be fixed by changing the host name on the Mac.
If you follow the guide below to change the hostname on a Mac this should resolve this problem. If you are not sure about trying this or after doing this you are still not able to send mail please contact us.
1. Open a Terminal window and enter the following command scutil --set HostName newhostname replace newhostname with whatever the you want to call your Mac. Use the following requirements, it must begin with a letter and can contain letters and numbers with no spaces. Try to keep it under 64 characters as well.
2. Click on the Apple icon, then System Preferences. In there, should be an option called Sharing. If not there will be a show all button at the top, click this, then click Sharing.
3. In the window this brings up click Edit
4. In the window this brings the Local Hostname field to contain the exact same thing you set the hostname to in the terminal
5. Back into the System Preferences page and click on Network
6. Select the Location option at the top and in the menu that pops up click Edit Locations
7. Click the plus button and give the new location any name.
8. Once this is done the computer may loose all connectivity. If the computer uses Wi-Fi, then click on the Wi-Fi option on the left of the network pane and then reconnect to the network without having to re-enter security keys or anything.
9. If you use Ethernet, make sure Ethernet is selected on the left and check through the advanced options, you might need to do a DHCP release and renew for it to start working.