The fee for "Mail Service of Process" under Section 118.052(3) is for the clerk's service of process by certified or registered mail. The fee is the same amount that sheriffs and constables are authorized to charge under Section 118.131.
Tex. Loc. Gov't Code § 118.063
MAIL SERVICE OF PROCESS
Acts 1987, 70th Leg., ch. 149, Sec. 1, eff
Official source: Texas Constitution and Statutes. Reproduced from public-domain Texas statutes; confirm against the official source for the current text. Not legal advice.