You can use either IMAP or POP3 to access your Gmail account. However, Outlook will NOT accept my password for the SMTP server. Upon restart, the 'Enter your user name and password for the following server' message pops up once for the server, and when I hit 'OK,' Outlook accepts my password, and the error ceases. I am able to receive email when I restart my Outlook. I tried ports 25 and 587 today, but no luck. For the past several years, Outlook SMTP has been set to port 465 (SSL/TLS) with no problems. This time, I've tried port changes, and I can see on support forums that other people have had similar problems over the last few months. I've assumed something was going on with Google, they resolved it, and my problem ceases.) (In the past, when I've received this pop up, I've spent hours troubleshooting, and then 1 or 2 days later, the pop ups eventually cease on their own. The 'Enter your user name and password for the following server' message keeps popping up for the server.
My primary email is set up as POP/SMTP, and as of approximately 3 days ago, I can no longer send email from Outlook. My back-up Gmail is set up as an IMAP/SMTP account, and it's working fine (no jinx).
