A catering company manager told a customer, "You were probably bottle feed till late teens", in an angry email exchange that has gone viral around the country.

Margaret McHugh of the Gourmet Food Store in Auckland also told Hayley Johnstone, an accounts and event manager at Ray White in Auckland, "I expect you still believe in Santa Clause".

The online argument has been posted on blog sites such as Spareroom and Kiwiblog, drawing comments such as, "How to kill your business in fewer than 36 hours".

It began when Ms Johnstone sent an email to Ms McHugh last Thursday asking if she could cater for 30 people on Monday. She listed the food she wanted and asked for a quote.

Ms McHugh replied, saying the food would cost $13 a head.

A series of emails continued throughout the day with Ms Johnstone querying the quote.

Ms McHugh did not reply to an email sent at 8.05am on Friday until early Monday, and that's when her attitude became tense. "You placed an order last Thursday and have NEVER confirmed your order for Monday AFTER 3 emails," she wrote.

"You asked for a quote which you were given then queried the prices against the website. Why ask in the first place? May I suggest you read the Home page of our site regarding pricing.

"I personally don't have the time or inclination to sit on the computer all day playing email ping pong. Please confirm your order by 9am this morning some 7 hrs before the function begins ... Incidentally we are going to be selling our house very soon and question your companies professional practises if this incident is anything to go by. Regards Margaret."

Ms Johnstone replied with a brief, "That is the rudest email I have received in a long time. We will not be requiring your services again."

It was then that Ms McHugh started a personal attack on Ms Johnstone. "Get into the real world young lady ... Re rudest email tells me once again you are not in the real world and haven't fully matured but it will happen. You were probably bottle feed till late teens ...

"And you thought my first email was rude. I expect you still believe in Santa Clause."

Instead of replying, Ms Johnstone sent the email to colleagues who then forwarded it their friends. Within hours the exchanges travelled the country.

Ms McHugh told the Herald she had no comment. Ms Johnstone did not return Herald calls yesterday.