If you are still in the old email format (Zimbra), from the Inbox page go to Preferences>>>>>>.Email>>>>>Email Deletion Schedule. There you can see what time setting you have for the Sent folder. If you are in the new format (Appsuite), they should be kept indefinitely until you delete them. There is no schedule you can edit.
Thank you for the reply but I need a little clarification if you don't mind. I believe I am on the "Appsuite" version because I see that specified in the url address line. Would I only see Preferences >>> Email if I was still on "Zimbra" version? I am guessing that is the case because I do not see Preferences anywhere. Please advise - Thanks.
The old Zimbra format looks like this-------------------
The new Appsuite format looks like this---------
So to answer your question-------yes, Preferences only appears in the old one. In the new one, you access your settings by clicking on the gear icon in the upper right corner of the Inbox page, and then on Settings.
How are you accessing your email? With a browser and the webmail interface, or on a mobile device or what? They should save by default. There is no setting you have that can change it. Try signing out of the account and back in again. Also-------
Try clearing out your browser's cache/browsing history. When you have done that, close out the browser and re-start it in a fresh session. If that doesn't do it, then try using a different browser.
I was able to fix mine. In Outlook I went to File/Account Settings and double clicked my IMAP account then clicked More Settings/Advanced and unchecked Do Not Save copies of sent items.
Thanks everyone for giving my ideas on where to look.