1. Notice by mail shall be deemed received three calendar days after the notice is deposited with the US Postal Service, first class postage, fully prepaid, for mailing to the addressee at the addressee's last known mailing address. Failure of the addressee to actually receive notice shall not invalidate the proceeding.

2. Posted notice is deemed given when the sign is first posted.

3. The requirement for notice shall be deemed satisfied as to any person who, in any manner, obtains actual knowledge of the time, place, and subject matter of the hearing prior thereto.

4. Appearance and testimony or comment on the merits of the proposed action by any person at a hearing, or submission by any person of written comment directed to the merits of the proposed action at or prior to the hearing and after the proceedings was initiated, shall be deemed a waiver of such person of any defect in notice.