I want to communicate by email with my leads and contacts but I am unsure of which email address I should use. Should I use the general email address of my company or should I use my own agent email address?
If you integrate email with Sell, you should use your own agent email address. Sell is not meant for tracking all the people who contact you for support at the general support address of your company. Not everyone who sends an email to your support team is an opportunity to close a deal. For capturing all the emails sent to your general inbox, use the Zendesk platform.
If you install the Zendesk Sell app in Support, your agents can use the Send note to sales feature that allows them to notify your sales team about possible opportunities.
If you still prefer integrating the general email address of your company to Sell, messages aren't synced to Sell unless they are associated with an existing lead or contact. For more information, see this article: Adding suggested people as a lead or contact.