If you install the 64-bit version of Office, then Sage 50 will not be able to use Outlook to send messages. Now that 64-bit Office is the default for Office 365, you need to watch for that as step one. However, yesterday, on a new install of Sage 50, it wasn't working even with the 32-bit version of Outlook.
We got the error:
Sage 50 cannot communicate with your e-mail program. Please ensure that your email program is MAPI-compatible and that it is the default MAPI client
You also need to have Outlook configured as the default mail program. The Mail program in Windows was configured as the default. So, we changed that to Outlook. Still no luck. Same error.
The final fix for me was adding a registry key. According to a few people in discussion forums, without that key, Sage 50 doesn't load the mapi32.dll that's required to send email. Silly that this is still happening.
In the registry at HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows Messaging Subsystem, I needed to create a new String Value (Reg_SZ) named MAPI with a value of 1.
Some of the web pages I reviewed during troubleshooting: