A search through the internet for the Error 2293 message gave lots of responses but nothing that could help. Luckily a second computer didn't have the problem so I went to send my test program to the second computer. I right clicked on the file and selected Send To, Mail recipient and was surprised to find this feature also didn't work.
That actually was a good thing as it showed the problem was a system problem and not a Microsoft Access problem. Again a search of the internet revealed many responses but nothing that could help.
I tested an email link in Excel and it worked. So clicking on a link would created an email for me. That meant it had to be something not related to email URL. When I checked the Send To feature that called MAPI. Most likely this was installed using Microsoft Office.
I decided to run a repair for Microsoft Office 2010, the version installed on the computer. Microsoft Access 2016 is installed on the computer but Microsoft Office contains Outlook and this is I suspect what would install MAPI.
It turned out I was right and the repair fixed the problem. The client could now send emails using the buttons in Microsoft Access that used SendObject.
What caused the problem I don't know. It may be possible installing Microsoft Access 2016 after Microsoft Office 2010 caused an issue as the client suggested the email feature hadn't worked for some time and possibly since the change to the full version of Microsoft Access 2016. Previously the computer only had Microsoft Access 2010 runtime installed, but was upgraded as the new computer had Microsoft Office 2016 and Microsoft Access 2016. This may have been the case because once Microsoft Office 2010 was repaired the test program I had written no longer worked and there was a missing DLL.
Problem fixed and client happily using their Microsoft Access system they've now been using for over 20 years that started with Microsoft Access 1.0 and now runs under Microsoft Access 2016.
Kelvin Eldridge
Online Connections
IT support.