Outlook 2013 sends outgoing email but about two weeks ago stopped receiving incoming mail. It keeps asking for password for att.net account but username and password has not changed, nor have settings for pop account. Why would it send but not receive? Fix?

The server settings for att.net are available at Get Email Server Settings - Email Support where you will also find information about updated security issues.

Different settings are used for incoming and outgoing messages.

__________________
Graham Mayor - MS MVP (Word) (2002-2019)
Visit my web site for more programming tips and ready made processes www.gmayor.com

Solving this problematic situation includes various methods based on what the exact cause of occurrence of this ‘not receiving some emails in Outlook’ issue. There are 10 efficient solutions mentioned below that users can try for resolving MS Outlook email receiving error issues in their Outlook account in Windows OS.

1. Cause: Outlook is not connected to the Internet
Solution: Users should first try to determine whether their computer is connected to the Internet or not. One can use a Web browser to check that they can access the Internet sites. In case, if someone is using a local network then, try to access any website to make sure that the internet is working or not. If the internet connection works fine then, verify that Outlook is online. For this, go in Outlook menu and make sure Work Offline option is unchecked.

2. Cause: Some POP and IMAP email accounts using SMTP requires authentication
Solution: If all the Outlook settings are correct yet, still if you are facing MS Outlook mail receiving problem in Outlook 2007 and other versions then, one can try to turn on the SMTP authentication. Below are the steps for this:

In Outlook, click on Tools tab and select Accounts
In Accounts wizard, choose the account
Now, under the Outgoing Server, select More Options
In the Authentication pop up, choose the authentication type and enter the credentials
3. Cause: Incorrect POP or IMAP settings in Outlook
Solution: Sometimes the incorrect POP or IMAP settings in the user’s Outlook account stops it from receiving email messages. Thus, to check the account settings and to fix Outlook sending and receiving issues, follow the below given steps:
Go to POP and IMAP Account Settings and make sure that filled details are accurate:

Your Name: Sender’s name that they would like to appear on emails
Email Address: Your full email address
Account Type: POP3 or IMAP
Incoming mail server: For POP or IMAP accounts it should be mail.papamail.net
Outgoing mail server (SMTP): For POP or IMAP accounts use mail.papamail.net
User Name: Your email account username
Password: Your email account password

I hope this will be helpful!
David Boon

@DavidBoon: When responding to questions, kindly keep your answer relevant to the question asked. Scattergun approaches that include solutions to problems the OP doesn't have are not helpful.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]