If you're sending emails through an SMTP server, verify that your server is correctly configured and can send emails. You can test this by emailing directly through the SMTP server outside the application.
Test whether our application can send emails using SMTP using Mailtrap-
Sign up for a Mailtrap account: Visit https://mailtrap.io/ and sign up for an account. Mailtrap offers free plans for basic usage, which should be more than enough for testing.
Create a new inbox: Once logged into your Mailtrap account, create a new inbox. This is where your test emails will be delivered.
Get your SMTP credentials: After creating a new inbox, go to its settings. You will find your SMTP settings, such as hostname, port, username, and password.
Configure your PHP application: Now, you need to configure the PHP application to use these SMTP settings for sending emails.
If you get the emails in Mailtrap, the SMTP integration is working.