Commas and capitalization in English letters

I have noticed that people with a German-speaking background often mix up conventions when writing letters and emails in English. For example, in German, the text directly after the greeting is considered to be a continuation of the greeting itself. Therefore, the first word starts with a capital letter if it is a noun or name but with a lower-case letter if not.

Examples for the beginning of a letter

Including the commonly used blank line after the greeting, we could start a letter with

Sehr geehrte Frau Schmidt,

vielen Dank für ihren Brief.

In English, things are slightly different. The line directly after the greeting is considered to belong to a new sentence and therefore begins with a capital letter:

Dear Ms. Schmidt,

Thank you very much for your letter.

Examples for the ending of a letter

In German, you are not supposed to use a comma after the closing at the end of your letter/email and before your signature. The following example is therefore correct:

Mit freundlichen Grüßen

Max Mustermann

On the other hand, in English, the comma should not be dropped:

Sincerely yours,

Mini Mouse