In using Dear Sir, Dear Madam, or Dear Ms., Sir or Madam or Ms. stands in place of the person's real last name. So, yes, both are capitalized. However, this is just for business letters.
Exemptions:
"Dear sir," I said, "do not correct my grammar!"
"Dear sir, let me get the door for you."
Yes, in a formal or professional greeting, "Everyone" should be capitalized. However, in a more casual setting, it is not necessary to capitalize it.
No. It's not necessary. It should be--- Greetings to all.
"Parents" is typically not capitalized in the greeting of a letter. It is only capitalized if it is used as part of a proper noun, such as "Dear Parents Association."
Yes, "Dear Team" should be capitalized when used as a greeting to address a group of individuals collectively.
Yes, "Pterodactyl" is supposed to be capitalized as it is a proper noun referring to a specific genus of pterosaur.
Yes, the first word of a greeting is typically capitalized, such as "Hello," or "Hi," to show proper punctuation and etiquette.
"Godspeed" is typically capitalized when used as a standalone expression or as a formal greeting. In other contexts, such as within a sentence, it may not require capitalization.
Earth, as in we live on the planet Earth, is supposed to be capitalized. Earth, as in the dirt we walk on, is not supposed to be capitalized.
Usually, yes a phase of the moon is supposed to be capitalized.
No, it shouldn't be capitalized.
No it shouldn't be capitalized.
Yes, "Hindenburg" should be capitalized as it is a proper noun referring to the German airship LZ 129 Hindenburg.
Yes, America should be capitalized.
no
No, but the names of individual languages are capitalized.
Yes, Siamese would be capitalized.
Yes.
Yes.
The word "not" is typically not capitalized in a title unless it is the first word, a proper noun, or part of a hyphenated word.