If that particular employee wishes to rejoin, you can very well asked him regarding gap of 02 months. You can show him letters dispatched by your office which are returned delivered (Here your mode of delivery of letters has utmost importance).
I feel at this stage you may ask him to furnish his explanation regarding absenteeism and after receiving his reply if not satisfactory to your management, you may take necessary actions against him. As per my opinion (although i am not having core knowledge of H.R.) you must give him every opportunity to defend his issue so that in future if aggrieved employee makes his mind to decide the matter in court, in such an event and in that event you should have enough documentary evidence so that you can easily plead the court that we have given enough and every opportunity to aggrieved employee.
Sorry i can't provide you draft letter right now because it depends upon what type of correspondence/s you have made to aggrieved employee.