This appeal is from an order entered pursuant to CPA 37 (d) (Code Ann. 81A-137 (d)) striking defendant's defensive pleadings and entering judgment against him by default for his failure to appear on three occasions at the times and places noticed for taking of his deposition. 2. Although it is the better practice to make a specific finding of wilfulness, we have held that it is not reversible error for the trial court to fail to do so (Smith v. Byess, 127 Ga. App. 39 (1) (192 SE2d 552); Merrill Lynch, Pierce, Fenner & Smith v. Echols, supra), particularly where, as here, the motion for sanctions alleges wilful conduct. Morton v. Retail Credit Co., 128 Ga. App. 446 (196 SE2d 902). See also Lee v. Morrison, 138 Ga. App. 332; Swindell v. Swindell, 233 Ga. 854 (213 SE2d 697); 4A Moore's Federal Practice 37.05. 3. Failure to maintain contact and cooperate with counsel about the pending litigation so that discovery can be made is wilful misconduct. Smith v. Byess, 127 Ga. App. 39, supra; Carter v. Merrill Lynch, Pierce, Fenner & Smith, 130 Ga. App. 522, supra; Houston Gen. Ins. Co. v. Stein Steel &c Co., 134 Ga. App. 624, supra; Swindell v. Swindell, supra. 4. The motion to impose sanctions was properly served upon defendant's attorney by mail. "Service by mail is complete upon mailing." CPA 5 (b) (Code Ann. 81A-105 (b)). 5. Remaining enumerations are without merit. 6. The motion to assess penalty for a frivolous appeal is denied. Harper & Matthews, Eugene Harper, Robert B. Matthews, for appellee. | 
