Good question.
CongressLookup is more of a “bridge” that uses Google Maps API and the Sunlight Labs Congress API (now managed by ProPublica). The Congress API did have an email variable but it was essentially useless as nearly all Congresspeople now use contact forms to cut down on spam.
We have added some hooks that you may be able to use for this purpose. If you look in our FAQs it gives you examples:
Q: Do you have hooks to modify the output?
A: Yes. As of version 2.1.8 we have added the following hooks:
“congress_results” filter to modify array returned by api
“congress_field” filter to modify field title
“congress_value” filter to modify field value
“congress_output” filter to modify output per field
CONGRESSLOOKUP HOOK FILTERS EXAMPLES…
If you need additional hooks they can be added.
We also offer a JavaScript input area under the custom shortcode section that might also be helpful to you.
If the preceding information was not helpful to you, please let me know.