Try these steps to fix Gmail SMTP not working
This is a common problem when SMTP was not working in Gmail to send or receive emails. Fixing it is child's play. In this section, we will provide troubleshooting steps to resolve the issue and correct SMTP server settings. To fix the problem, you can allow less secure apps using the following section. But before that, you need to disable two-factor authentication. That is how:
Disable two-step authentication
When Gmail smtp not working, it may be because the 2-Step Verification option doesn't allow less secure apps. Here are the steps:
First, sign in to your Gmail account.
Now tap on Manage your account.
Choose Security in the left panel.
After that, from the Google login, tap on the 2-step verification option.
Now you need to enter the password of your Gmail account.
Click the Disable button to disable 2-Step Verification.
Confirm it by clicking the Deactivate button.
After disabling two-factor authentication, follow the steps given to allow less secure apps.