The Pipedrive Outlook calendar integration lacks a bit for our user's needs. For example, items are added into Outlook as UTC time, there isn't a default 15 minute reminder for them, not enough body, description, and activity type data appears in the Outlook item, etc.

So I am using the Pipedrive API along with the Microsoft Graph API to perform a custom sync. So far so good. Although for editing existing Outlook calendar items that are synced is a bit of a challenge. To keep things simple, I am looking to store the Outlook calendar event ID in an available Activity field. That tells me that the Pipedrive activity has already been pushed into Outlook. I'm only looking for one-way sync. Anything in Pipedrive will push or update in Outlook.

At this point all I need is some rather obscure Activity data field that will hold the value. I tried using the conference meeting client field, but it doesn't allow enough characters. It only allows 20 characters, while the Outlook calendar event ID appears to be 152 characters long. 

Any suggestions about an Activity field that I can use? Preferably one that the users won't accidentally overwrite.

Thanks all!