I received an external meeting invitation in Mail, but the Daylite Mail Assistant does not present me with an option to accept or decline the meeting; it only shows the option to record the email in Daylite.
Why is this problem occurring
Likely, your user contact card in Daylite does not have your email address added to it.
To rectify this, find your contact card in Daylite and check to see if your email account address is added to the contact card. If it is missing, edit the contact card and add the email address. Once you've done this, restart Mail and check the email with the external invitation again.