Exchange Online Hybrid environment, encountered an issue with the ESM service where the error describes unsupported MAPI version even though the Outlook version was upgraded to 15.0.5119.1000, MAPI reported by ESM.wlog stated it was 15.0.4795.1000.
Windows Server 2016
Outlook 2013 Retail (15.0.5119.1000)
12:17:27 MAPI provider is Microsoft Outlook 15.0.4795.1000
12:17:27 ERROR: To support Exchange Online mailbox, Outlook 2013 SP1 is required and the version must be equal or greater than 15.0.5041.1001!:
Outlook MAPI DLL path has the incorrect information, Changing the registry entries for MAPI resolved this.
Looking in “HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail\Microsoft Outlook\” the “DllPathEx” points to a MSMAPI32.dll located in “C:\Program Files\Microsoft Office 15\root\VFS\ProgramFilesCommonX86\system\msmapi\1033\msmapi32.dll”, checking this DLL details are version 15.0.4795.1000, so it appears that even though we upgraded Outlook, the MAPI version remains as original.
Changed the “DllPathEx” to point to “C:\Program Files\Microsoft Office 15\root\office15\OLMAPI32.DLL”, resolved the issue.