Telemart 
Gmail now lets you write an email and schedule a sending time. The recipient will receive your email at your scheduled time. Google added this feature in April 2019. It’s now built into both Gmail’s websites and the app.
How to Schedule an Email on Desktop:
Go to your Gmail on desktop, click the down arrow to the right of the Send button and click “Schedule Send”. Gmail provides various options like Tomorrow Morning and Tomorrow afternoon. You can also preset your time and date in the schedule and send and schedule your email for a few years. Gmail will let you schedule emails up to the year 2068
How to Schedule an Email on iPhone or Android:
In the Gmail app for iPhone or Android, you can easily compose your scheduled emails. Compose your email, then instead of clicking the “Send” button, tap the menu button on the top right corner of the screen and then tap “Schedule Send.” Same as on desktop you can choose an option like “tomorrow morning” or preset your custom date and time.
How to Cancel a Scheduled Email on Desktop:
You can view your scheduled emails by clicking “Scheduled” in the side panel of the Gmail interface on your desktop. Open The schedule emails. To cancel your scheduled emails, click “Cancel Send” at the top right corner of the email. Gmail will save that message in a draft you can modify its content and re-schedule the email and resend it immediately.
How to Cancel a Scheduled Email on iPhone or Android:
In the Gmail app for iPhone and Android, you can cancel your scheduled emails, tap the menu button at the top left corner of the screen and click “Scheduled” in the menu. Tap the email that you want to cancel. Same as on desktop, tap “Cancel Send” at the top right corner of the emails to cancel sending it. Gmail will save that email in the draft. You won’t lose the email unless you chose to discard the draft
