I have a Yahoo address email that I use for participation in public forums (sparing my normal addresses from spam), and I post using a proper email program, rather than some awful interface in a webbrowser. But recently I found I was unable to send mail through Yahoo's SMTP server with my mail client, getting an unhelpful error notice. Yahoo had changed their authentication requirements, without notifying us users, and the error message doesn't provide any useful information about what went wrong, nor how to fix things. The actual problem was that they required you to change your password, but you would only find out about this if you logged into their website: When you log into the site, you're told to change your password, and it won't let you do anything more (on their website) until you do.
A confusing thing about this issue was that I was still fetching my mail (using my original password), so I wasn't expecting the sending failure to have anything to do with passwords. I was suspecting the failure was down to another change in encryption requirements. A previous configuration change, much longer ago, was that they required you to use an encrypted authentication method (before, you didn't have to), but they forwarned you about this long before it was required.
Email encryption and authentication techniques are far from standardised, and it can be awkward to find a compatible combination between your software and their server (protocols, port numbers, and what user information they want from you). Out of the various things that I tried, the following variations of server configurations worked (outlined below). It took more messing around than was necessary thanks to my email program not giving me any easy way to change a password (without resetting every password in it, which I didn't want to do), the useless error message not triggering the email program to automatically ask you to enter a new password, and too much quitting and restarting was required to try sending with different options selected. So, I haven't tried out all the possiblities that might work. All I know for certain is that encryption and authentication are both required, and the following combinations of settings did work:
| Server type | SMTP |
|---|---|
| Server | smtp.mail.yahoo.com |
| Server requires authentication | ticked |
| Use secure connection | TLS or SSL encryption |
| Authentication type | Plain |
| Username | type in your full email address |
| Remember password | ticked or unticked (as per your own preferences) |
| Server type | SMTP |
|---|---|
| Server | smtp.mail.yahoo.com.au |
| Port | 587 |
| Server requires authentication | ticked |
| Use secure connection | TLS encryption |
| Authentication type | Plain |
| Username | type in the bit of your email address that's to the left of the @ sign |
| Remember password | ticked or unticked (as per your own preferences) |
| Server type | SMTP |
|---|---|
| Server | smtp.mail.yahoo.com |
| Port | 25 |
| Server requires authentication | ticked |
| Use secure connection | TLS encryption |
| Authentication type | Plain |
| Username | type in your full email address |
| Remember password | ticked or unticked (as per your own preferences) |
| Server type | SMTP |
|---|---|
| Server | smtp.mail.yahoo.com |
| Port | 465 (this port number was auto-selected by the TLS option, below) |
| Server requires authentication | ticked |
| Security encryption method | TLS on a dedicated port (this auto-selected port 465, above) |
| Authentication type | Plain |
| Username | type in your full email address |
| Remember password | ticked or unticked (as per your own preferences) |
The first time you try to send mail through it, Evolution will ask you to enter the password (there isn't anywhere to set the password in the configurator). And, if you opted to let Evolution remember your password, you will only get re-asked to enter a password if the server sends an appropriate error message that the email program recognises (which didn't happen, this time).
NB: My Yahoo email address is using the yahoo.com.au domain, hence the second set of configuration choices with a .au smtp servername.
Although the authentication type is plain, this is taking place inside an encrypted connection, so your credentials are not transmitted in the clear.
I don't use Evolution to get my mail from Yahoo, so I have no configuration examples for that (though it ought to be something similar; selecting the same kind of encryption, letting it choose a default port number, and using your email address and password as your login credentials).
I get my mail by having a periodic fetchmail daemon download them to the local mailserver every so-many minutes. I get my mail, this way, so that all my mail from various addresses is centrally stored on one mail server. This is the line in my .fetchmailrc configuration file that does that:
poll pop.mail.yahoo.com.au proto pop3
user "faked_address@yahoo.com.au", with password
"reallybigsecret" ssl, is "tim" here options
fetchall;
The bolded portions pertain to my mail service; the address for the Yahoo mail server, my yahoo email address, its password, and the mailbox name that they go into in the local mailserver. Naturally, I've used faked example data for the address and password. Fetchmail does allow you to abbreviate the configuration lines, but the longhand version is far less cryptic.