Zimbra Collaboration Suite does not natively support delayed sending or scheduled sending of emails. However, there are workarounds available, either by using add-ons or third party applications to do so.
Here’s an example using Boomerang for Gmail (an extension available for Chrome, Firefox, and Safari):
1. Download and install Boomerang for Gmail according to the instructions provided on their website.
1. Set up your Zimbra email account to work with Gmail (via POP or IMAP).
1. Now, compose an email on Gmail as you normally would. At the bottom of the draft screen, you will see a red button saying “Send Later”. Click on it.
1. Choose when you would like the email to be sent. You can have it sent at a specific time or choose from one of the predetermined options, e.g “In 2 hours”, “Tomorrow morning” etc.
1. Click “Confirm”.
Remember this is more of a workaround and needs additional setup and tools, Zimbra itself doesn’t have direct facility to send delayed emails as of now.
