Fewer people are reading marketing emails, according to a new survey.

The study, conducted by agency eROI concluded: “We continue to see a decline in read rates across the board as more and more email clients are adopting the ‘images off’ default setting.”

A further decline in read rates was expected throughout 2007 because only 4% of users change their email client’s default behaviour to disable images.

Furthermore, eROI said open and click rates on weekends were now less than last year, though this could be seasonal – more people could be outdoors playing football in the park during the summer.

Emails that are opened on the weekend are more likely to yield clicks, however.

Monday, Wednesday and Thursday proved the most effective day to send out messages, with people more likely to read and click emails on those days.

During weekdays, the survey showed a spike in the number of emails read at 11am and 4pm but most were clicked at 6pm as work winds down.

“Consider segmenting your list into morning, midday, evening and late night delivery and see how your campaigns perform,” eROI said.