We are using email templates for Contacts in order to send customers information. In certain emails we need to be able to code the URL using merge field values for contacts. This is because these URL parameters should not have to be entered into the web page by the customer when we already know them from the CRM. We have routinely done this with our other mailing systems, specifically Active Campaign.  The URL we need to code is presently in a button in the Contacts Email template.  The URL is in this form as required by the outside system:

https://some-outside-url.com?email=${Contacts.Email}&field__first-name=${Contacts.First Name}&field__last-name=${Contacts.Last Name}&field__phone-number=${Contacts.Phone}

We recognize that spaces in the URL are problematic, but using %20 isn't logical because this should have already been populated by the Zoho CRM contacts module. 

Does anyone have an idea on how we could do this?