Can't send emails from Outlook via smtp server since update KB4551762 today.

After installing Windows updates today, I am able to receive emails through the pop server but cannot send emails through the smtp or smtpa servers.  A pop up box keeps asking me to input my valid email and says that my server rejected the password.  If I email from my phone (connected to my wifi), they go through no problem with the password.  Tech support with my internet server said it is not a problem at their end but a problem with Outlook.  Anyone else having this issue?  Anyone know how to fix it?