Preview email for a single Client
@param number $client_id id of the client
@param number $template_id id of the email_template

client_id	integer, required
template_id	integer, required

Create a letter for a single Client
@param number $client_id id of the client
@param number $template_id id of the email_template
@return value: id for the letter of the client (the PDF will be generated by workers and will be reported to the company)

client_id	integer, required
template_id	integer, required

Create letters for multiple Clients
@param string $client_ids comma separated list of clients
@param number $template_id id of the email_template
@return value: id for the task that will generate and merge the PDF documents

client_ids	string, required
template_id	integer, required

Create letters to the clients that are in filter
@param number $filter_id id of the filter to run form
@param number $template_id id of the email_template
@param string $excluded_ids ids of the clients to exclude
@return value: id for the task that will generate and merge the PDF documents (the PDF and merge will be generated by workers and will be reported to the company)

filter_id	integer
template_id	integer, required
excluded_ids	ids
included_ids	ids
selectedIds	ids
selectAll	string
exceptIds	ids

Create letters to the clients based on last selection
@param number $template_id id of the email_template
@param string $excluded_ids ids of the clients to exclude - optional
@param date - (default: CURRENT_DATE)
@return value: id for the task that will generate and merge the PDF documents (the PDF and merge will be generated by workers and will be reported to the company)

template_id	integer, required
excluded_ids	ids
included_ids	ids
date	date
selectedIds	string
selectAll	string
exceptIds	string
customerSearchString	string
filter_id	string
order_by	string
order_direction	string