update (25 April 2017): SADC countries that don't need a visa: Botswana, Lesotho, Malawi, Mauritius, Namibia, Tanzania, Seychelles, South Africa, Swaziland, Zambia and Zimbabwe. [src.]
The government of Mozambique has approved new visa regulations on 21 February 2017, so that travellers from countries where Mozambique has an embassy or consulate are now eligible to get their entry visa at the port of entry. The new visa is valid for 30 days and allows travellers to leave and re-enter the country within the 30 day time frame. Until now - at least according to the official visa regulations - only travellers from countries where Mozambique has no diplomatic representation could obtain their visas at Mozambique's border stations.