In each of the past two years I've represented clients who were sued over quotes contained in e-mails. The cases were dismissed, but not before the clients were put to the expense and inconvenience of having to defend the lawsuits. In each situation the problem was a lack of detail in the quote as to what would not be provided, and a lack of legal disclaimers.
When you prepare a quote for goods or services consider whether you have made an assumption regarding a substantive characteristic of what you are supplying, then limit the scope of your quote by stating that sum quoted is contingent on that assumption being true. If the price was calculated using information provided by the customer, identify that information. If the customer asked about an alternate, but decided not to purchase that alternate, confirm that in the quote.
By legal disclaimers, I mean disclaimers of implied warranties and other Uniform Commercial Code terms with regard to the sale of goods, and disclaimers of industry standards or commonly accepted practices with regard to the sale of services. Disclaimers help you avoid a legal obligation which would otherwise be placed on you by law. Drafting legal disclaimers requires knowledge of the legal obligations the law places on you, and therefore should be prepared by your lawyer. Once written, legal disclaimers can be made a part of a digital form on which you can place the substantive portion of the quote.
As we conduct more of our business through electronic communication, it has become more commonplace to summit quotes electronically, by e-mail or otherwise. I understand submitting a quote as quickly as possible may secure a sale before it can be secured by a competitor. However, no matter the form of communication used, the quote should be worded so as to avoid a misunderstanding between you and your customer as to exactly what is to be provided.