SMTP suddenly stopped working (outgoing email)

All of a sudden, my OUTLOOK on both Android & PC wouldn't CONNECT. So it prompted me to Reset my Password. So I did that, successfully.  I updated both Phone & PC clients.  However, I can ONLY receive email (IMAP) - not SEND (SMTP)  .. every time I try to send, I get a pop-up to "enter your user name & password" for SMTP.COMCAST.NET ..   I did that - countless times. It refuses to accept my new password.  I verified this my logging into the XFINITY Web Client and can see my mail and send just fine. I can't get this darn SMTP thing to work on either my PC or Phone. this is driving me nuts. Why so difficult?  Any suggestions greatly appreciated.