Mailbox is a pretty handy email client based on Mozilla Thunderbird, so it looks like this, but the developers say they have more functionality. It should be noted at the outset that the customer may be comfortable with those who usually write emails with attachments, such as photos or documents, videos, and so on. You can send photos directly to the client interface and then upload them to Picasa right away.

I would also mention the convenient tab bar, there is a set of special buttons, such as pictures, links and some others, they allow you to open all the attachments in the message with one click, you can also open the links separately in Windows. Additionally, you can perform a set of required actions with each message attachment. AIDA64.5.70

The mailbox has its own search engine, you can immediately find the necessary information in the e-mails sent to you, such as the name or e-mail address of the contact, the desired link or image, any text. After completing the search, your results can be viewed in a special form. The mailbox is easy to use, Russian support is available, I really liked the interface, I have no complaints.