ERPNext able to receive email but not able to send email

Refer to the below post for a relevant bug

I manually define each Email Domain, even for GMail, Yahoo, etc, in addition to my own-domain email accounts, and do not rely on the predefined services in the drop-down selection box. I’m not too sure where the email configuration detail is stored, in a file or in the DB, but to confirm my configuration has taken affect, I download an import template to view the detail.

I know phpMyAdmin has a feature to constantly check which tables have changed.
DBeaver can do a search for a specific value across all tables

DBeaver > F5 > Search > DB Full-Text > TextToSearchFor > Search > …

allows you to find any data in the DB.

You can also monitor your file system to see changes to any file with

find ~/frappe-bench/ -type f -mtime -0.1 -ls
grep -ir “SearchFor” ~/frappe-bench/

Also use the browser’s DevTools > Network > Headers > Form Data to indicate which API methods are being called when the changes are made in the WUI.

Other than that, I’m fed up with the poor SMTP implementation. It’s not a new complaint and the forum is filled to the brim with people having had problems with it way back many years.