Bit late now but Gmail has disabled the less-secure app function as of 31 May so any old stuff (such as Windows Live Mail that I still use) won't work with Gmail.
Less secure apps & your Google Account
To help keep your account secure, from May 30, 2022, Google no longer supports the use of third-party apps or devices which ask you to sign in to your Google Account using only your username and password.
Important: This deadline does not apply to Google Workspace or Google Cloud Identity customers. The enforcement date for these customers will be announced on the Workspace blog at a later date.
For more information, continue to read.