At my airline, the 757 and 767-200, and the ER versions cannot dump fuel and cannot legally, without exercising emergency authority, cannot be landed at MTOW.
Our Company:
757 MTOW 240 MLW 198
767-200 MTOW 322 MLW 272
Figure 8,500 burn holding 757, and about 10,500 burn for the 767-200, it can take a long time to get down to MLW during a time which you must, if one engine, land at the nearest suitable airport.
767-300 MTOW 407 MLW 320, and we can dump.
Overweight landings are allowed at our company, but no bank of 30 degrees and no autoland.
Inspection is required after an overweight landing, but time and extensiveness is based on softness/hardness of landing.
Other operators may have different numbers or limitations.