Comma after greetings like ‘Hello’, ‘Hi’ or ‘Dear’ in emails

Road sign, New York City

Greetings are the initial remarks that we use to greet an addressee in correspondence like ‘Hi’, ‘Hello’ or ‘Dear’.

Both British and American English make use of similar words for greetings in emails and letters. However, they may differ in punctuation usage. Additionally, the use of a punctuation system in emails may result from organization’s business culture.

In general, there are ‘rules’ such as closed punctuation for using commas with names and greetings for business letters. Some people imitate those rules in emails, while other people think those rules don’t apply to emails, because emails are less formal than business letters. Other people prefer the so-called ‘open punctuation’ which stands for the omission of characters and marks such as full stops (periods), colons, or commas in the address, after the salutation and in other parts of emails.

Comma after ‘Hello’, ‘Hi’
When the greetings in your email starts with ‘Hello’ or ‘Hi’, it is common practice to put a comma before the name of the person you are addressing. Direct address necessitates this comma usage to define the intended recipient of your greeting, marking proper etiquette in both personal and professional communication. It is also standard practice to put a comma or a full stop after the name of the person you are addressing, for example:

Hello, Patricia,
Hi, Patricia.

If you want to set a tone of excitement in an informal email, you may use an exclamation point to end the greeting with. Example:

Hi, Patricia!

Comma after ‘Dear’
When your email’s content is informal and personal, use Dear and a comma after a greeting, for example:

Dear Patricia,
Dear Mom,
Dear Dad,
Dear Mom and Dad,

When your email’s content is formal and official, especially in business correspondence, or when you don’t know the recipient personally, there are some differences between British or American English.

In British English, commas are used after both formal and informal greetings, for example:

Dear Mr Smith,
Dear Professor Smith,
Dear Prof. Smith,
Dear Director,
Dear Sir or Madam,
Dear Managing Director,
Dear Valued Customer,

Meanwhile, the greeting in American English is usally followed by a colon, for example:

Dear Mr Smith:
Dear Professor Smith:
Dear Prof. Smith:
Dear Director:
Dear Sir or Madam:
Dear Managing Director:
Dear Valued Customer:

Note:
You should avoid using the highly impersonal Dear Sir/Madam or To Whom It May Concern in emails and try to find out exactly whom you are writing to.

Comma after ‘Good morning’
According to most grammar resources, the greeting ‘Good morning’ should have a comma after it and before a person’s name. However, many people often get rid of the comma in informal letters and writing. Examples:

Good morning, Patricia!
Good morning, everyone. We have a busy day ahead.
Good morning, Mrs Vincent,
Good morning, Professor Smith,

Comma after ‘Happy birthday’
Because you typically say ‘Happy birthday’, directly to someone, you should use a comma after the ‘Happy birthday’ but before their name. Example:

Happy birthday, Patricia!

Abrreviations:
Mrs – to address a married woman
Miss – to address an unmarried woman (rarely used now)
Ms – to address a woman whose marital status you don’t know; also used to address an unmarried woman

The abrreviations Mr, Mrs etc. are usually written without full stops (Mr) in British English and with full stops (Mr.) in American English.

Photo: Road sign, New York City