Recently I was asked to share some information with respect to the limitations on CRM 2015 outlook client. After a careful consideration, this are issues which might be addressed. The ones listed below are

the ones already mentioned by Microsoft and what i investigated for an old colleague for his specific requirements:

Home address can get moved to CRM Address 2 field. Be aware of following mapping:

Cannot add a related record while you are offline on CRM 2015 Outlook client.

While offline, you can’t add a related record type by using the Add button (+). So, the user experience has to be add the related record type while you’re online, and then go offline.

Inserting a picture from file into an appointment is not supported.

If you do add so, inserted picture will convert to text.

Some fields will synchronize data even if they are not part of field synchronization settings.

For example, in case of task certain fields will need to be synchronized by the CRM system.

Synchronization for Activities and Service appointments is unidirectional.

Changes made to Service Appointments and Activities in CRM will update in CRM for Outlook when you synchronize, but the reverse is not true. When you make changes to Service Appointments

or Activities in CRM for Outlook, the changes are not synchronized to CRM.

Sharing Calendar on Outlook for somebody else to work and sync your appointments is going to cause synchronization issues.

Consider the scenario where Managers share their calendars to their subordinates so that they can plan appointments for them. This will have synchronization issues as it is not same as the manager themselves syncing their appointment.

This is the summary of extract from TechNet article and also based on learning from investigation on CRM outlook client myself.

Note: IF you have more information to add, leave in the comments and I will update the content of this article.

Hope it helps!