app/views/petition_mailer/process_explanation_mail.text.erb
<%= t("mail.dear") %> <%= t("mail.request.dear") %> <%= @petition.office.name %>,
<%= t("mail.request.procedural",{
petition: @petition.name,
petitioner: @petition.petitioner_name,
reference: @petition.reference_field
}) %>
<%= t("mail.request.signoff", {
petitioner: @petition.petitioner_name,
office_email: @petition.office.email
}) %>