I keep getting this message whenever I send a email to a friend what does it mean? I was told that it is invalid but I have sent emails before

00.000.000.000 does not like recipient.

Remote host said: 550 Mailbox <bob@pnutbutter.com> cannot

receive mail.

Giving up on 00.000.000.000.

numbers and email address changed for security purposes

That is an SMTP Delivery Code generated by YAHOO!'s mail server. q-mail is a type of server mail handling system. Sometimes the action (failed, refused) is given with a 3-part qualifier which is the status (7.1.1) which will give you the very specific reason the mail failed. This looks like only part of the header, do you have the rest to include, or could you check for an expanded header?

The 500 series remote host response generally indicates a server error, perhaps an unrecognizeable command. Delivery will be tried for a certain number of times over a certain period before it gives up and returns the error.

Maybe the users mailbox may be full and cannot receive other mail.

This does not look like a problem on your end. Try to send again and see if it will work, sometimes they are transient errors.

It means for some reason your account is not able to send valid e-mail. Are you sure your account is fully active, have you missed any payment recently if you were using a Plus account or another payed version? If you are not using a paid version, and you keep getting this message, I suggest you contact Yahoo Customer Service right away. You should be able to send e-mail. Are you receiving e-mails OK? Anyway, go to the Yahoo Mail Help and put in a question like "Why is all my e-mail coming back undeliverable?". Then when an answer comes up, even if it seems totally unrelated, (which happens a lot ) click on any of the answers. A new page will appear with the answer, and at the bottom is a question "did this fix your issue?" or some such wording. Click on the link "No, contact customer service" or some such wording. A form will appear which you fill out as directed. In the text box explain your problem in detail and add your information regarding the system you are using, your connection type, and other information requested, then click Send. You should get a response within one to two days, and hopefully it will tell you what to do to fix this problem.

Good luck finding out what is wrong and getting it fixed. Have a nice day.