Can we lock unsesirable e mails

Yes, it is possible to lock or block unwanted or unsolicited emails, also known as spam emails. Here are some ways to do so:

Spam filters: Most email providers, such as Gmail, Yahoo, and Outlook, have built-in spam filters that can help block or flag suspicious emails. You can also adjust the settings to be more aggressive or lenient in filtering out spam.
Blacklisting: You can add senders of unwanted emails to your email provider's blacklist, which will prevent them from sending you emails in the future.
Block sender: Most email providers allow you to block specific senders or domains from sending you emails. You can do this by marking an email as spam and then selecting the option to block the sender.
Spam reporting: Many email providers allow you to report spam emails to their abuse department. This can help them identify and block future emails from the same sender.
Third-party spam filters: There are also third-party spam filters available that can help block unwanted emails, such as SpamAssassin, SpamSieve, and Cloudmark.
Email client settings: You can also adjust the settings in your email client (e.g., Outlook, Thunderbird) to block or filter out unwanted emails.

Some popular email clients and their spam filtering features:

Gmail: Has a built-in spam filter that can be adjusted in the settings. You can also use Gmail's "Report spam" feature to help improve the filter.
Outlook: Has a built-in spam filter that can be adjusted in the settings. You can also use Outlook's "Junk email" feature to block or allow specific senders.
Yahoo Mail: Has a built-in spam filter that can be adjusted in the settings. You can also use Yahoo Mail's "Report spam" feature to help improve the filter.
Thunderbird: Has a built-in spam filter that can be adjusted in the settings. You can also use Thunderbird's "Block sender" feature to block specific senders.

Remember to always be cautious when opening emails from unknown senders, and never respond to or click on links in suspicious emails.