Hi Andrew,

Simply use a lookup control on form the with a filtered look up to find email address of person/company you entered in the form

This will give you a drop down on the form to select email address

If you wish to get absolute email address on the form you need to use list look up function

1) Create a variable using 'listlookup' function

2) Add the variable to a label if you need to to just view email address

3) If you need to update a a form/list field, you will need a rule to update the field

Let me know if you have further questions related to this implementation

Kind regards,
Ashish

Hi 

I assume you are using the lookup function formula(varible) to get the field on the form

1) Create a column on your SharePoint list may be "email"

2) Add the list field to the form 

3) Update list field using a form rule 

"If 'carrier' is filled then 'email' value = 'varEmail' ( your variable)"

4) Use the column in the workflow to send emails

Let me know if you need further help writing the rule

Regards,

Ashish

You may do in another way by using a query list action on the workflow to query for 'email' from the contacts list with a filter 'if form field carrier value is equal to carrier on the contact list' 

Store result from query list in a text variable say 'varEmail'

Use 'varEmail' for you run if with your desired condition