In neetoCRM, there are a couple of places from where you can send emails
On the Lead/deal/contact page:
Mails Tab -> Send EmailOn the Lead/deal/contact listing page:
Bulk actions -> Send email
For sending the email, you can either use the lead/deal/contact specific email address or use your synced account email ID. Both options would be present in the From dropdown if lead/deal specific email feature is enabled and your Google account is also synced. Once you send the email, the same email will be preselected as the default option for next time. You will always have an option to select between either of the two.
If you haven't synced your Google account, then by default the lead/deal specific email is selected.
Similarly, if the lead/deal specific email feature is disabled and the Google account is synced then by default google account email ID will be used.
If lead/deal specific email feature is disabled and the Google account is not synced, then the send email option will not be present.