You may not know it, but there’s a good chance that some of your friends, family and colleagues find your email messages annoying – even offensive.

In many cases, they aren’t even reading past the first paragraph.

So says a new survey of 1,000 working adults conducted by San Francisco-based app maker MailTime, which found that a large percentage of emails are perceived by their recipients as rude, impersonal and overly long.

The survey describes a litany of common mistakes found in email messages and the negative reactions they engender. For instance:

• 93 percent of those surveyed said they disapprove of emails that are insensitive in tone;

• 88 percent said they dislike email that isn’t personally addressed to them;

• 81 percent said they disapprove of messages that are too long; and

• 87 percent disapprove of emails addressed to multiple recipients that prompt a stream of “reply all” responses.

In general, “reply all” can be a dangerous beast, according to Susan Krauss Whitbourne, a psychology professor at the University of Massachusetts Amherst.

Not only can it annoy disinterested recipients of the original message, she said, but it also can result in situations where your casual, curt or sarcastic reply might be appropriate for the original sender but not for other recipients.

“Needless to say, watch out for that holy terror of the ‘reply all’ option,” Krauss Whitbourne wrote in a September Psychology Today article. “Emails that come from a group are especially dangerous if you don’t pause before responding.”

The MailTime survey also asked respondents to choose the phrase they hated most from a sample group of email messages. The most reviled phrase in all of emaildom was, “Please advise.”

MailTime co-founder Charlie Sheng said the rising use of smartphones to read and send email has exacerbated the annoying nature of some common mistakes.

For instance, long, meandering emails that take seemingly forever to get to the point are even more obnoxious when the reader has to keep scrolling down on his or her tiny touchscreen, she said.

“It was very annoying to 65 percent of the people,” said Sheng, whose company’s iPhone app converts email messages into a format that resembles text messaging. It also gives advice, such as warning the writer when an email is getting too long.

The survey revealed an important lesson for those of us who use email to conduct business: Long messages aren’t just annoying. They’re also ineffective.

Nearly one-fifth of all respondents said they never read past the first paragraph. Three-fourths said they don’t read all the way through emails longer than three paragraphs. Nine out of 10 said they don’t finish emails longer than seven paragraphs.

So remember that lengthy screed you fired off to your delinquent employee the other day? Your employee probably doesn’t.