People are fed-up with what is being called "second degree spam", e-mails from companies about products they are not interested in, says a survey.
'Second degree spam' is set to rise
Even if people signed up to be sent news or offers, NCorp's survey says over half see them as irrelevant spam.
From December, EU rules to tackle spam will force companies to ask customers for permission before sending e-mails.
As a result, second degree spam will "worsen", says NCorp's Martin Blackburn, damaging consumer loyalty.
Big turn off
"Sending spam is completely socially unacceptable, whatever form it takes," says Mr Blackburn, NCorp's managing director.
But one in six spam e-mails arriving in UK inboxes is from companies sending information about irrelevant products or services, according to the survey.
The problem is set to worsen with the UK and EU ban on unsolicited communication, thinks Mr Blackburn, as more businesses use opt-in mailing lists as a way to sell goods.
People find these e-mails highly irritating if they have not been tailored to what interests them.
As a consequence, many are turned off and distrustful of the company and what they offer, Mr Blackburn suggests.
Over 95% of people questioned in the survey said they thought companies had an obligation to make more of an effort to only send out information pertinent to them.
"I think businesses are being lazy in designing their communications," says Mr Blackburn.
"It is easier in their minds to send the same thing to everyone, but where is the effort?"
"If you imagine walking down the street on holiday in the evening and you get stopped outside every restaurant trying to get you in, it is annoying to the point it puts people off going back there."
"That is a fairly close analogy to this kind of spam because you are getting annoyed by things you didn't ask for."
If companies do not make more effort to personalise e-mails to people, e-mail marketing could potentially be damaged permanently, thinks Mr Blackburn.
'Toothless' spam ban
Spam now accounts for more than half of all e-mail traffic, and legalisation banning unsolicited e-mails sent from within the UK to personal addresses seeks to curb that.
But it will not impact spam in the way it was envisaged when the "toothless" legislation was set out, Mr Blackburn says, with spammers moving towards using opt-in mailing lists to "cover themselves".
There also needs to be an enforcement of standards to make it easier for people to unsubscribe from mailing lists.
Currently, it is not made obvious on many mailing list e-mails how to opt-out once you have started receiving them, but Mr Blackburn suggests unsubscribing should be no more than a couple of clicks away.