As Mr & Mrs.
* Informally means casual so you would address a husband and wife by their first names. Formally is when you would use Mr. Doe or Mrs. Doe.
Mr & Mrs James Angstrom Jr.
Major and Mrs . . .
When addressing a deceased husband's wife, it is respectful and compassionate to refer to her as the widow or the late husband's wife. It is important to offer condolences and show empathy towards her loss.
Dr. Mary Smith and Mr. James Doe
Just address the card to Mr and Mrs (husband's name). It's perfectly okay to address the husband and wife but to avoid offending the wife just do the Mr and Ms last name and you're probably safe.
Governor and Mrs./Mr. Smith
How about Mr. and Mrs.
Pastors George and Martha Maloney
* Major & Mrs. John Doe
Doctor Smith and his wife Reverend Smith (assuming she is using his last name).
Pastors George and Martha Maloney