Helping people with computers... one answer at a time.
Desktop email programs will often prompt for information they need to do their work. In order to send or receive email, a username and password are required.
Why does Microsoft Outlook ask for a username and password when I press send and receive?
There are two levels to this question, and I'm going to address them both.
One: in addition to an email program you need an email account in order to send and receive email.
Two: your email program needs to know about that account.
Two-and-a-half: OK, sometimes your email program can get confused.
Occasionally, I get questions from folks who are essentially asking why it's not enough to just get an email program like Outlook or Outlook Express to send email, without having to sign up for an email service.
Your email program is not your email.
By that I mean, your email program - be it Outlook, Outlook Express, Thunderbird - or even web interfaces like Hotmail, GMail or Yahoo - are merely tools that you use to access your email. They don't, by themselves, give you an email address or make it possible for you to send and receive email.
You need an email account.
You can get an account from any of several different places. You can sign up with free email services like GMail, Hotmail and the like, for example. If you have an internet connection at home, it's very likely you already have an email account through your ISP.
An email account is typically identified by three bits of information:
"Username" and "email address" are sometimes the same, but not always.
Your username and password identify you to your email service, and your email address identifies you to the world.
Once you have an email account, if you're using a desktop program to access your email, you'll need to configure that program with the same three bits of information: username, account and email address.
Some programs will ask you to configure only username and email address - the first time you try to download or send email they will prompt you for the password, and then offer to remember it for you.
If at some later time your password ever changes, the program will notice that the old password it has didn't work and will prompt you again expecting you to enter the new one.
Read that last paragraph again, and notice what happened: the program tried to connect and send or receive email, and that attempt failed due to a bad password. Figuring that the password was bad, it asks you for the correct one.
In fact it doesn't have to be a password failure for the program to ask you.
It your email program attempts to send or receive and that fails for reasons that might possibly be due to a bad username or password, the program could prompt you for those again. Note that it's not saying that the username and password are bad, it's saying that the failure it's experiencing might be due to a bad username or password.
And of course that "or not" is where a lot of confusion arises. I've seen email programs prompt for username and password simply because the computer wasn't connected to the net. Re-entering the username and password isn't going to fix that.
The most common possibilities for your email program prompting you for your password again include:
You changed your password, and your email program simply needs to know the new one.
You're having connectivity problems to your email server. Try again later, or from a different location.
Your email program is slightly confused. I've seen Thunderbird get into this state. Exit and restart your mail program.
Your email account has been closed or suspended.
Someone else changed your password, or your account has been stolen.
Your email service no longer provides POP3/IMAP/SMTP access as used by desktop email programs.
You don't have an email account. See the first part of this article.
There are probably even more possibilities, but those are the most common. In general check to make sure your password is correct, perhaps log into a web-based interface if your email service provides one, restart your email program, or wait a while to see if the problem goes away.