Go to Settings > Account > Outgoing Email.
If you are changing to a new email address, enter the new address in the 'Sending Email Address' box and if necessary change the 'Descriptive Sending Email Address' box. I.e. if you are changing your business name to Best Stays Ever, you might change the first box to 'info@beststaysever.com' and the second box to 'Best Stays Ever'.
In the next section, you will need to enter your new email server details. Please refer to this page regarding these settings, especially if you are using outlook or g-suite and are having issues.
Once you have entered all the required settings, make sure you click 'Save'. You can then click on the blue 'Send Test Email' button to make sure the settings work. If you see an error and can't figure out the solution, please submit a ticket to us.