Can't open new email to send new emails or 'reply '

try saving it as new first, then try replying to it I have had this happen if the person I am replying to has blocked me; not your case if you are able to get through with a new email.

Open your email program. Look for 'compose', 'create' or 'new email' and add the email address to the individual you want to send the mail to. Enter a subject. Write your text. Click on send, and you are done. Now you can wait to see what the reply is in the same email program.
If you need to respond back, just hit the reply button and enter your text. Once again hit send.

I'll assume this is a general problem and not only on occasion. I'll also assume that you're using a "mail" app to read your mail.
If so: Some providers do not accept outgoing mail from a server other than what they see for your computer. They will Deliver, but if you're using wifi or a cell connection, it looks too much like someone else hacking in.

The workaround is to use a browser and the provider's "webmail address". I use Safari and bookmark my access. It remembers my password and turns ut to be easier to delete old mail. Log on to your provider's website and look for its mail options.

Hi Richard. Thers a good chance you have mail preferences setup to compose new emails in "plain text". And/Or, "Use the same message format as the original message", meaning if you reply to someone who sent you an email that is in Rich Text Format, then your reply will be in Rich Text Format but, if they send you an email in Plain Text Format, then your reply, and possibly any forwarding will be sent in Plain Text also.

For website addresses to be "clickable links" in mail, you need to ensure all emails you send, forward, or reply are in Rich Text Format.
go to Mail... Preferences... then select the Composing tab and ensure Message Format is set to "Rich Text".
Further below in the same tab you will see "Responding" and a tick box for Use the same message format as the original message (Respond using Rich or Plain Text).
If you always want to respond or forward in Rich Text only and every time, then deselect that option.
All links should work and be clickable from then onwards.

You can highlight a non working website link in the email body, right click, then select "Link" then "Add Link" to make it clickable but, you will receive a notification about converting this message to rich text format?"

Basically, the links will not be clickable if you are setup to compose new emails in Plain Text. Nor will any replies or forwards you send that are changing to Plain Text to match the format received by you from others.
Always end, reply and forward in Rich Text Format

Hope that helps.
Regards
Paul

Usually, the "Reply" button or command does not actually send a reply. Instead it merely opens up an editor of some type that lets the user compose a reply. Nothing is actually sent until the user invokes "Send."

Try it yourself. Send yourself an email, then reply to it.

On any FixYa page, click your username in the upper right corner, click "My Profile," click the "My Account" tab, change the entry in the "Email Address" field, then click the "Save My Information" button.

Try sending a message to yourself and then replying to it. The recipients might have a cached entry in their address book causing a the reply to be delivered to a different address.

If you have another email account with Hotmail or Gmail, try sending back and forth between them and your Yahoo account and use them for testing.

Does this happen with everyone or just one of your e-mail contacts?

If it's happening with everyone, you may need to contact Yahoo's support team to investigate the issue.

Hope this helps!

Yahoo Mail has 2 modes: 1.Classic mode and 2.Standard mode I guess you're in standard mode,I suggest you switch to classic mode, I hope it could help you
Good luck

Switch to classic mode of yahoo mail, I think it could help you

Try using the original non-beta account. The older account profiles seem to work better, and there is some lag (server slowness) in Yahoo in general, if something is just not working, either click on the link once more or refresh the page.

Hope that helps!
- CoolDragon.