Ms. B, a resident of Manila, is temporarily working in Singapore. Mr. C files a complaint against her. How can Mr. C serve the summons?

DEF Corporation, a foreign company, has a contract with GHI Inc., a Philippine company. A dispute arises, and GHI wants to sue DEF. Can GHI serve the summons in the Philippines?

Mr. D files a complaint against a person whose address is unknown. He has exhausted all means to find the defendant. How can he serve the summons?

A sheriff attempts to serve a summons to Mr. E at his residence three times, but no one is present. The sheriff leaves the summons with a neighbor. Is this valid service?

FGH Corporation files a motion to dismiss a complaint against it, citing lack of jurisdiction over the person. Does this constitute voluntary appearance?

Mr. and Mrs. I are sued as spouses. The sheriff serves the summons only to Mr. I. Is this valid service for both?

Alpha Corp., a domestic corporation, has its principal office under receivership. The receiver, Mr. X, operates from a temporary office. A process server serves the summons at the original principal office, which is now vacant. Is this valid service?

Mrs. Y, a Filipina, resides in Canada but owns a condominium in Makati. Mr. Z files a case involving the condominium. He serves the summons by registered mail to Mrs. Y's Canadian address. Is this valid?

Beta Inc., a foreign corporation, has a liaison office in Manila but claims it's not "doing business" in the Philippines. A summons is served on the liaison officer. Is this valid?

Mr. A files a case against "John Doe," whose identity and address are unknown. He publishes the summons but later discovers the defendant's actual name and address. Does he need to serve a new summons?

Gamma Co., a corporation, is dissolved but still has assets being liquidated. A summons is served on the former corporate secretary. Is this valid?

Mr. B, a government official, is sued for actions taken in his official capacity. The summons is served at his private residence. Is this valid?

A sheriff attempts to serve a summons at a gated community. The security guard refuses entry, citing community rules. The sheriff leaves the summons with the guard. Is this valid?

Delta Ltd., a foreign corporation, has a Philippine subsidiary. A summons intended for Delta Ltd. is served on the subsidiary's president. Is this valid?

Mr. C files a case against his estranged wife, Mrs. D, who is believed to be in hiding. He serves the summons by posting it on the door of their last known shared residence. Is this valid?

Epsilon Inc. files a motion to dismiss, questioning the court's jurisdiction over the subject matter and person. Does this constitute voluntary appearance?

A prisoner is sued. The summons is served on his lawyer. Is this valid?

Zeta Corp. changes its principal office without updating its SEC records. A summons is served at the old address. Is this valid?

Mr. F files a case against a deceased person. He serves the summons on the deceased's known address. Is this valid?