Salesforce has various different types of fields such as picklists, checkboxes, text area, lookup IDs and others. Lookup IDs are common for fields like Account Owner or Sales Rep or CSM.
With Sendoso, you might want to insert in the Account Owner or Sales Reps name as a variable in a handwritten note or a printed-on-demand card. Like this:
And you may also want to sync the Sendoso Sender back into your own Salesforce fields. Like this:
Here comes the challenges... Lookup Field types are IDs. For example, the Lookup Field for Sales Rep might be shown as "Joe Smith" but Salesforce reads them as "00Q1N00000ZN8QU" which makes inserting and mapping to Lookup Fields impossible. There is a workaround though!
1) Create a new Formula(Text) field and then insert the desired field (i.e. Account Owner name)
2) Hide that field on the Contact record.
3) Insert that new field into the Sendoso template or map back to the field.
You're good to go!