sc.judiciary.gov.ph/jurisprudence/2012/november2012/178789.pdf
"x x x.
There is no question that the Arcinues’ motion failed to comply with the requirement of Section 11, Rule 13 of the 1997 Rules of Civil Procedure which provides:
SECTION 11. Priorities in modes of service and filing. —
Whenever practicable, the service and filing of pleadings and other papers shall be done personally. Except with respect to papers emanating from the court, a resort to other modes must be accompanied by a written explanation, why the service or filing was not done personally. A violation of this Rule may be cause to consider the paper as not filed.
Section 4. Answer to complaint-in-intervention. — The answer to the complaint-in-intervention shall be filed within fifteen (15) days from notice of the order admitting the same, unless a different period is fixed by the court. (2[d]a, R12)
But the above does not provide for automatic sanction should a party fail to submit the required explanation. It merely provides for that possibility considering its use of the term "may." The question is whether or not the RTC gravely abused its discretion in not going for the sanction of
striking out the erring motion.
The Court finds no such grave abuse of discretion here. As the RTC pointed out, notwithstanding that the Arcinues' failed to explain their resort to service by registered mail rather than by personal service, the fact is that Lim's counsel expressly admitted having received a copy of the Arcinues' motion for judgment by default on December 7, 1998 or I 0 days before its scheduled hearing. This means that the Arcinues were diligent enough to
file their motion by registered mail long before the scheduled hearing.
Personal service is required precisely because it often happens that hearings do not push through because, while a copy of the motion may have been served by registered mail before the date of the hearing, such is received by the adverse patiy already after the hearing. Thus, the rules
prefer personal service. But it does not altogether prohibit service by registered mail when such service, when adopted, ensures as in this case receipt by the adverse party.
x x x."