Bulk Deleting Emails get rid off from 793 error

Trying to delete the emails in Gmail leading to 793 error ? don't worry here is a solution to clean all those hundreds of thousands of emails which are there from past year or less. To do this you need run a small script using Google Script.
First go to this link https://script.google.com/
Then start a script and copy paste the below script into Google script and save it (click the little clock button).
This is for your triggers. You can set up how frequently you want the script to run (I did mine for every minute).

function batchDeleteA() {
  var batchSize = 100 // Process up to 100 threads at once
  var threads = GmailApp.search('label:inbox older_than:2d');
  for (j = 0; j < threads.length; j+=batchSize) {
    GmailApp.moveThreadsToTrash(threads.slice(j, j+batchSize));
  }
}

How to stop a sent mail after hitting the send button in Gmail

Gmail is one of the most commonly used mail service by every internet user. It's is common that every human makes mistake but sending an email with mistakes might may lead to problem sometimes.So, Gmail has a feature that we can undo a sent mail.

By mistake or unintentionally we send an email we can undo it in Gmail and the email will be saved in drafts and can be corrected and resend it again.

Lets see how to Undo a sent mail:

• Log in to your Gmail account and go to mail settings.

• Now go to 'Labs' section in setting menu.

• Now make a search for"Undo send" extension in labs. There comes cool Gmail beta plugin which helps you to undo a sent mail.

• Enable the "Undo Send" and save your mail settings and refresh your page.

• Test it by sending an test mail to anyone and now you will find a small Undo option besides it to get that email back, click that Undo and your email will back to draft for future use.

How To Enable Gmail Preview Pane

Provides a preview pane to read mail right next to your list of conversations, making mail reading faster and adding more context.
1. Sign-in into your Gmail account.
2. Goto Gmail Settings –> Click Labs section.
3. Search for Preview Pane.

4. Click on Enable radio button and hit Save Changes.

5. Once you’ve enabled it, there will be a new button on top of the email list which will enable you to activate the vertical split or horizontal split and switch between the full list view and the split view.

6. That’s it. The currently selected message will be displayed in full to the right or below the email list.

Restore gmail contacts

There are many times in life when a do-over can come in handy. Perhaps you clicked “Send” on an email that was better left unsaid, or “Delete” on a contact before realizing you still needed it. Just like Gmail lets you unsend a message, you can now have a second chance with your contacts too.

We’ve added a new feature to Google Contacts that allows you to revert your contact list and undo any mistakes made up to 30 days in the past. Let’s say you accidentally deleted a bunch of contacts or wiped the contact data from your Gmail account by mistake while syncing to another device. Visit Gmail’s Contacts section, select “Restore contacts” in the “More actions” menu, and choose the time you would like to revert to.

Your contacts will be restored to exactly the same state they were in at that time — any contacts that didn’t exist then will be deleted and any that have since been added will be deleted. Don’t worry, you can always undo this change by restoring again if you didn’t get the time right.