,Filtering is the way request packets pick out mail accounts to which the requested operation will be applied. The mail operator uses filtering in most of its operations.
The filter node used in operations create and update is presented by the mailnameFilterType complex type (mail_input.xsd). This data type is structured as follows:

plesk_mailname.xsd). This filter can pick out one to many mail account existing on the same domain.
When filtering mail accounts, we never specify the entire mail name. The domain part of it is specified by the domain_id node, and the mail user name is specified by the name node within the mailname section.
<packet version="1.4.2.0">
<mail>
<update>
<add>
<filter>
<domain_id>12</domain_id>
<mailname>
<name>ann</name>
<mailgroup>
<enabled>true</enabled>
<address>techdept@example.com</address>
<address>findept@example.com</address>
<address>techgroup@example.com</address>
</mailgroup>
</mailname>
</filter>
</add>
</update>
</mail>
</packet>
The packet above modifies settings of the ann@example.com mail account (a mail group) with several new mail addresses.
The mail operator uses two more types of filtering (type GetInfoAdvancedFilter, type mailFilterType). These types are designed for particular cases and considered in the relevant sections (Getting Mail Account Settings and Deleting Mail Accounts, respectively).