How to connect Contacts and Accounts board with Activities board?

I need to connect contact and account board with activities board using match automations and helper columns basically by the format(Contact+Account). Activities are created from deals board in my scenario. But the issue is email and activities doesn’t just allow any columns to be mapped here even if it is a text column.

Columns which can be mapped:

  • Activity content

  • Activity type

  • Create date

  • End date

  • Source item name

  • Start date

  • Status