LONDON: Half of UK adults make no distinction between email marketing messages and spam, despite the £4.8bn ($7.6bn; €5.7bn) per year spent by brand owners on this channel.
A new report, conducted by TNS for data analytics specialist Kognitio, also shows that 59% of users support tougher legislative controls on the distribution of these messages.
Meanwhile, 73% believe companies send emails to them without taking the relevance of the message to the recipient sufficiently seriously.
And almost two-thirds (63%) said they would rather do household chores than "face their email inbox".
Roger Llewellyn, ceo and president of Kognitio, said: "Email marketing is a huge business for companies worldwide.
"However, it should never be allowed to frustrate and confuse consumers to the extent that this research shows."
Another problem identified for advertisers was that their terms and conditions were not sufficiently easy to understand.
The convoluted prose meant that many web users did not read the necessary information.
In response, the report said advertisers should be "responsible" with their emails and to try to target them more precisely.
"Reputable companies should keep their email marketing focused, concise and transparent," Llewellyn added.
Data sourced from Kognitio; additional content by Warc staff