If you are not sure they are separated or divorced then address your envelope to both of the. If you know for sure they are separated then send a separate envelope to each one.
When addressing an envelope to the wife of a doctor who is not a doctor herself then and he is Dr. John Doe, then address the envelope to her as Mrs. John Doe or Ms. (Mrs.) Jane Doe.
The proper way to address that letter would be "Mr. and Mrs. John Doe."
In the inside address of a formal letter, you would typically write "Mr. John Smith and Mrs. Jane Smith" to address both individuals. If you are referring to them collectively, you might write "Mr. and Mrs. Smith." Ensure to include any titles or names as appropriate for the context of the letter. Always use proper punctuation, such as a period after "Mr" and "Mrs" if adhering to American English conventions.
If this is a personal letter to just this individual then you would address it: Mrs. Jane Doe or you could put Mrs. John Doe.Some women would find it offensive to call them by their husbands full name and just forgetting theirs altogether so address it Mrs. Jane Doe.
Govenor and Mrs. Beebe
The best way to address your letter to a Minister is to Reverend and Mrs. _______
To;The Reverend and Mrs (Insert name)
Captain and Mrs.....
Dear (Mr. / Mrs.) XX
If you're addressing it to both of them - It would be: Mr & Doctor Smith OR Mr & Mrs Smith - depending on how well you know them.
If this is a formal letter, you address him by his rank.For instance, if he is a private:Dear Private and Mrs. Smith.Likewise if he is a Colonel:Dear Colonel and Mrs. Smith.