These bots are used by e-mail providers and ISPs to support their individual account offerings, they will perform tasks such as domain verification and ownership checks. Select the appropriate bot if you use the services of any of the listed providers
This robot is used by the Yandex.Mail system to verify domain ownership rights.
Yandex Calendar bot
The Yandex.Calendar bot used for syncing with other calendars. YandexCalendar regularly downloads calendar files by users' requests. These files are often located in directories prohibited from indexing, so this bot does not respect a general bot block robots.txt, but instead, the useragent YandexCalendar needs to be specifically disallowed.
Yahoo Mail Proxy is a content fetch proxy that retrieves the page content of URLs that are embedded within emails sent to Yahoo Mail users.
This is a crawler for the email service from the Russian Portal Mail.RU.
Google Image Proxy
This bot collects image assets for Google GMail, allowing images to be displayed in e-mails, but stopping the e-mail user from being tracked as the images are serviced via a Google proxy. This bot does not check for Robots.txt, so enable this if you want your image content to be viewed by GMail users.