1. Make effort to learn about etiquette (these days known as "netiquette") involved in writing emails. There are loads of good reference websites and books about internet which will tell you basics. I know it might seem a bit precious to attach so much importance to social niceties when internet is basically very informal. However, whether we like it or not many people do take online etiquette very seriously. So if you're writing emails for business, you should assume that your recipient may well be one of those...

2. Never send and preferably don't even try to write an email if you're angry, upset, drunk, or otherwise not in total control. If you have a heated conversation with someone on telephone you can sometimes fudge things over. But with emails, once you hit "send" whatever you've written is there, carved in tablets of stone, for as long as recipient wants to glare at it. The old adage about "counting to ten" before responding couldn't be more true here. Only send angry emails if you can handle, or really don't care about, recipient's resultant feelings!

3. One thing that you may not think of is that it can be useful to consider carefully time you send your emails. To begin with it's always a good idea to avoid sending emails that coincide with Monday morning rush and Friday afternoon lethargy. In addition, I've occasionally found that emails sent to companies over weekend end up getting lost in cyberspace. And on a rather more subtle level, if your recipients see that you're sending emails on a Sunday morning or late at night, they may feel they can interrupt you for a business talk at same times. Although you may think it's cool to impress a client that you work all hours, your partner won't when same client calls you on phone at midnight.

In fact therapeutic benefits of laughter are now being harnessed by academia and business community into laughter workshops and other formalized chuckle sessions. Get workers laughing and you raise productivity, so it seems.

However it is extremely easy to get humor wrong. And a joke that’s sent to someone who doesn’t see funny side will create more ill health through raised blood pressure than a few laughs could ever cure.

So what’s answer? How do we harness humor and make it work for us, not against us?

People often say that internet’s international nature makes it an unsuitable environment for humor for fear of it not translating across national boundaries – and inadvertently causing offense. But there are a couple of simple rules which – although not universal panaceas that always work – can help you use humor without risk.

Use humor about situations, not people. If you think about it, butt of many jokes and other humor is a person or group of people, so it’s hardly surprising that offense is caused. The more extreme types are obvious - mother-in-law jokes, blonde jokes, women jokes, men jokes – but there are many more subtle ones too.

Then there are nationality gags. I remember in one year hearing exactly same joke (in three different languages) told by an American about Polish, by a Canadian about Newfoundlanders, by a French person about Belgians, by a French-speaking Belgian about Flemish, and by a Flemish person about Dutch.