64 selected
- Macau
- Madagascar
- Madagascar (British post)
- Madagascar - Illegal Stamps
- Madeira
- Mahra
- Malawi
- Malawi - Illegal Stamps
- Malaysia
- Malaysia - Federal territory
- Malaysia - Johore
- Malaysia - Kedah
- Malaysia - Kelantan
- Malaysia - Malacca
- Malaysia - Negeri Sembilan
- Malaysia - Occupation by Japan
- Malaysia - Pahang
- Malaysia - Penang
- Malaysia - Perak
- Malaysia - Perlis
- Malaysia - Sabah
- Malaysia - Sarawak
- Malaysia - Selangor
- Malaysia - Sungei Ujong
- Malaysia - Trengganu
- Malaysia [1900-1963] - Federation Malaya
- Maldives
- Mali
- Mali - Illegal Stamps
- Malta
- Maluku Selatan (South Maluku - Cinderella)
- Man
- Man - Calf of Man - Cinderella
- Manchukuo
- Marienwerder
- Marshall Islands
- Martinique
- Mauritania
- Mauritius
- Mayotte
- Mecklenburg-Schwerin
- Mecklenburg-Strelitz
- Memel
- Mexico
- Micronesia
- Middle Congo
- Mohéli
- Moldova
- Moldova - Gagauzia - Illegal Stamps
- Monaco
- Mongolia
- Montenegro
- Montenegro - Cinderella
- Montserrat
- Morocco
- Morocco - British post offices
- Morocco - French post offices
- Morocco - German post offices
- Morocco - Spanish post offices
- Morocco [1956-1957] - North Zone
- Mozambique
- Mozambique - Companhia de Moçambique
- Mozambique - Illegal Stamps
- Myanmar (Burma)
- Not filled in