Sending seasonal greeting cards to non-muslims

Can the following from al-ashbaah be used as a justification for sending seasonal greeting cards at Christmas time?
In al-ashbaah it states that if a person says regarding a non Muslim:”May Allah let his kingdom last for a long time” and his intention is that he may be given hidayat in future, or that the Muslims could benefit through his contributions of jizyah etc, then this is permitted.
Please provide a referenced answer.
Jazakallahoo Khayrun