Add info about AdGuard Mail Trackinf Protection filter

docs/general/ad-filtering/adguard-filters.md

@@ -26,6 +26,7 @@ This article is about the filters we create to use in AdGuard and other ad-block
     - **Other Annoyances** blocks elements that do not fall under the popular categories of annoyances. [View rules](https://raw.githubusercontent.com/AdguardTeam/FiltersRegistry/master/filters/filter_21_Annoyances_Other/filter.txt)
 
 - **Filter unblocking search ads and self-promotions** unblocks ads that may be useful to users. Learn more about this filter on [this page](../search-ads). [View rules](https://raw.githubusercontent.com/AdguardTeam/FiltersRegistry/master/filters/filter_10_Useful/filter.txt)
+- **Mail Tracking Protection** blocks tracking pixels embedded in emails to prevent senders from monitoring when you open messages and collecting information about your device or activity. [View rules](https://raw.githubusercontent.com/AdguardTeam/FiltersRegistry/master/filters/filter_25_Mail_Tracking_Protection/filter.txt)
 - **Russian filter** removes ads from websites in Russian. [View rules](https://raw.githubusercontent.com/AdguardTeam/FiltersRegistry/master/filters/filter_1_Russian/filter.txt)
 - **German filter** removes ads from websites in German. Originally based on the [EasyList Germany](https://easylist.to/) filter and subsequently modified by us according to the complaints from users. [View rules](https://raw.githubusercontent.com/AdguardTeam/FiltersRegistry/master/filters/filter_6_German/filter.txt)
 - **French filter** removes ads from websites in French. Originally based on the [Liste FR](https://forums.lanik.us/viewforum.php?f=91) filter and subsequently modified by us according to the complaints from users. [View rules](https://raw.githubusercontent.com/AdguardTeam/FiltersRegistry/master/filters/filter_16_French/filter.txt)

docs/general/ad-filtering/filter-policy.md

@@ -111,6 +111,7 @@ The goal of ad-blocking filters is to block all types of advertising on websites
 AdGuard tracking protection filters include:
 
 - AdGuard Tracking Protection filter
+- AdGuard Mail Tracking Protection filter
 - AdGuard URL Tracking filter
 
 ### The purpose of these filters
@@ -130,6 +131,8 @@ What it blocks:
 
 The **URL Tracking filter** is designed to remove tracking parameters from web addresses
 
+The **Mail Tracking Protection filter** removes tracking pixels embedded in emails to prevent senders from monitoring when you open messages.
+
 ### Limitations and exceptions
 
 Tracking protection filters should not block a tracker if blocking would disrupt the correct functioning of the website: