First, there was no GMail. There were Yahoo!, hotmail, aol, and other OK email services. At work, we were forced to use Microsoft Outlook. I happened to select Yahoo!. It had simple to use interface and it worked. Then Google created an exemplary GMail single-page Web client plus smart spam filtering on the server.
I opened an email account yakovfain@gmail.com. I’m not afraid of spam otherwise I would have written a naive yakovfain at gmail dot com. Yeah, right! Now I got two email accounts.
Yahoo! looked at GMail, and decided: “Me too”. But it’s easily said than done. It looks like their engineering team that works on Yahoo! email client had no budget to hire people with the right skills, and over the last several years their Web interface was steadily changing from bad to worst.
If there was a world competition for the Worst Rich Internet Application, Yahoo! mail client would have easily won the gold medal. Everything is inconvenient and non-intuitive there. Scrollbars barely work. You can’t simply highlight and copy the email of a recipient – need to go through a popup menu that will work every other time. You can’t create a filter to put messages on a particular folder. It simply feels bad.
I did’t want to close my Yahoo! mail account because lots of people have it in their Contacts. Finally they got me today. After complaining about it to my younger son, he just asked, why won’t you just forward all of Yahoo! emails to your Gmail account? And why wouldn’t I?
For years my GMail client is pulling all my work emails for our company’s mail server. I could have set Yahoo! the same way. But I didn’t want my Yahoo account to accumulate any emails sent to me. After quick search I found an easy way to set up the mail forwarding without storing. This is how I did it:
1. Click on the Gears icon on top right, and select Settings.
2. Select the Viewing Email on the left and then switch from Full Featured (tecommended by them) to Basic (recommended by me).
3. Select Option in the dropdown on the top right.
4. On the left hand side select Pop & Forwarding.
5. Enter your gmail address on the right and Forward only in the dropbox.
This way you still can keep your Yahoo! mail account, but all new emails will be forwarded to your gmail account. In the Mail Accounts section you can set your email address in the the Reply To box, so gradually, your contacts will get used to the fact that you’re using gmail now.
Hope this helps… for most of the messages. But Yahoo! can’t even forward the email properly. Sometimes it can blame your external accounts and even steal messages from it. Oh, this Yahoo!
yakovfain.com 
Hello Yakov. Why did you need to switch from Full to Basic view? Here is the way how to do it without view changing:
Mouse over the Settings menu icon Gear Icon | select Settings.
Click Accounts in the left pane.
Click Edit beside “Yahoo account.”
Select Forward.
Enter the address you want to forward your email to and select:
Store and forward – Email is saved to your account and sent to the forwarding address.
Forward only – All email is sent directly to the forwarding address.
Store and forward and mark as read – Email is saved to your account, marked as “Read,” and sent to the forwarding address.
Click Save.
It looks like their engineering team that works on Yahoo! email client had no budget to hire people with the right skills, and over the last several years their Web interface was steadily changing from bad to worst.
If there was a world competition for the Worst Rich Internet Application, Yahoo! mail client would have easily won the gold medal. Everything is inconvenient and non-intuitive there. Scrollbars barely work. You can’t simply highlight and copy the email of a recipient – need to go through a popup menu that will work every other time. You can’t create a filter to put messages on a particular folder. It simply feels bad.
I just wanted to say that >I couldn’t agree more with these observations.< As a yahoo Mail user of 15 years I read about changes in leadership at the Top of Yahoo Corporate Structure and when I read about their loss of market share, etc. I think to myself, "They don't need a new CEO! They need to listen to the little plebe at the bottom of their food chain who knows that their users are PEOPLE, and that a simple, even marginally(!) intuitive interface is what people want (and what Yahoo used to be like). It doesn't seem to me that going "from bad to worse" is inevitable, but apparently I'm wrong about that(?).
I know that I'll have a reader of One here; and I'm sure that others are saying the same thing all over the internet, but I just wanted to acknowledge your Statement of the Truth.
Their mail app looks as if their engineers had a goal to showcase the worst user experience possible. Any CS student would do better.