After completing several updates on Exchange 2013 due to another issue, we found that e-mail messages were going to the Drafts folder instead of the Sent Items folder. In addition the server was not receiving any messages either.
After further investigation we found that the Mail Transport service was failing, not immediately, which was why we didn't notice it after it was started. In this particular case the client had a secondary SMTP port configured for relay messages but that port was setup on both the Exchange 2013 CAS and Database servers but only one of the CAS server actually had the IP address assigned on the NIC. Once the relay SMTP port configuration was removed from the Database server the Mail Transport service ran fine and mail flowed through the system correctly.
One of the most common questions we get regarding mobile devices is how to setup an Apple iPhone with access to a corporate Microsoft Exchange mail system. This doesn't have to be a local system, it could be a hosted cloud Exchange server as well. Many people often will use a POP connection but this really doesn't allow the mobile device to exploit the full capabilities of the Microsoft Exchange services such as synchronizing contacts and calendars. So, get the full benefit of Microsoft Exchange by using the Exchange mail connector on the mobile device.
There are a couple of pre-configuration steps that you may want to take, especially if you have moved your Exchange service to a different hosting provider.
Most of the Microsoft Exchange technical notes do a great job of explaining how to move a recipient's mailbox from one database to another. But there is little to be found about moving the recipient resources to different database. The short answer is that it is the same process.
So you don't have to go looking for the details, here are the steps to follow.
This article is currently in progress in relation to a problem we have seen with configuring Outlook 2016 with Exchange 2013. This issue has a number of posts in general on the various support forums on the Internet but no definitive solution. As we find the solution to this we will post it here.
If you want to test the autodiscover for your Exchange server, use Microsoft Connectivity Analysis tool.