Think twice before you hit the send button to email and post comments on sites, says writing skills trainer Giulia De Cesare, if you can read it in a sarcastic tone of voice, chances are others will too. And before you know it, you've got a major slanging match online.

"Email is no longer simply a business communications tool. It is now 'the' business communications tool, one of the most critical enterprise applications, and the primary method organisations use to collaborate." Chris Miller, director of Product Management at Symantec.

Would anyone disagree with that? And yet, how many of us have actually had any training on the finer points of email? We've gradually increased our use of it and never really stopped to ask if we're doing so in the most effective way.

Let them eat Spam, not read it

Are you sure, for example, that all your emails are getting through? If a client uses a spam filter - and most do - what would get your mail tagged as spam, never to reach your reader's inbox? Most people now would know better than to include any words like special offer, free, congratulations, or, God forbid, Viagra in their subject lines, as these are the sort of key words that spam filters look for. But did you know that some filters also block any mails with no subject, or with attached files? Worth checking, next time a client says they didn't receive your mail.

Are you sending the right message?

Another problem with email and postings is the greater likelihood of messages being misunderstood, compared to phone calls or letters. Researchers have found that while recipients correctly understand the tone of a phone call 73% of the time, the success rate for emails is only 56% – a little over half. This is especially worrying because recipients actually thought they were correctly interpreting the emails 89% of the time!

There are several reasons for this: with an email you lack some of the input you'd get from a phone call, such as tone and emphasis of voice. People don't always realise this, because emails can be as immediate as phone calls. Another reason is that people mistakenly think others interpret things the same way they do.

These can contribute to 'flaming'. Someone finds offence in an email or comment on site and replies in kind, often stunning the original sender who intended nothing of the sort. They are in turn offended and before you know it, a major slanging match is going on - in front of an aghast audience.

Hosing down the flames

The most effective way to break such a cycle is to pick up the phone. Adding those vocal cues back into the communication quickly clears up misunderstandings. Not replying in the heat of the moment is another good idea, but something that's often hard to resist.

Before sending a possibly contentious email, try reading it back in a sarcastic tone: if you can do this, then there's a chance the recipient could also interpret it this way, so re-word it. If re-wording it doesn't help, then make a phone call instead, sending a mail after to confirm if you need a paper trail.

Something else to avoid in emails is the negative question: wasn't that report due yesterday? Weren't you going to talk to him? This kind of structure is often seen as implying criticism.

Email ate my life!

A survey reported by BusinessWeek online found a 14% increase in volume of email over a three month period. Many users report having hundreds of emails sitting in their inboxes. This can feel like an anchor holding you down, a paralyzing thing to face every morning.

How many emails do you have in your inbox right now? Having asked that, I've just guiltily checked mine, and whittled it down from 19 to 15. A few months ago, though, it was regularly between 200 and 300 mails. This is because, like too many people, I was using my inbox as a general filing system, and the more mail that was in it, the harder it was to do anything about it.

Another idea I've found useful is 'touch it only once!' Do something with each email the first time you read it - action and file it, delete it, even just tag it for follow-up. This saves you from that great time-waster of skimming repeatedly through the same mails before finally getting round to doing something about them.

Giulia De Cesare is a writing skills trainer with Plain Words and can be contacted on 01635 202013 or info@plainwords.co.uk