Almost a quarter of the top 100 UK businesses fail to provide an email address to non-customers, according to a new report from Eptica.

The 2012 Eptica UK Multichannel Customer Experience Study analysed the responses of 100 organisations via the web, email and social media channels, replicating research conducted in 2011.

In many cases results have deteriorated since 2011 – more than a quarter (28%) of companies performed worse this year despite being asked exactly the same questions through the same channels.

And the situation appears to be particularly bad for email customer service. As the penetration of smartphones increases email is becoming a more important method of communication.

It is vital for customer service, as it provides a written record of correspondence and means customers don’t have to wait around on the phone.

Last year we reported that Ryanair had been investigated by the EU for failing to provide an email address, instead requiring customers to pay 10p a minute to phone the call centre.

However the Eptica report shows that businesses appear to be moving away from email contact, with almost a quarter (23%) of companies failing to provide an email address for non-customers.

And companies that do respond to email aren’t doing a particularly good job of resolving queries. While two-thirds (64%) of businesses in the study replied to emails, only 39% provided an accurate response.

Furthermore, 51% of businesses didn’t immediately acknowledge incoming emails, which is extremely poor considering that the initial response can easily be automated.

Consumers also have to wait longer to get a proper response. The average time to receive a reply lengthened from 15 hours 31 minutes in 2011 to 25 hours 50 minutes in 2012.

The failure of businesses to respond via email is likely to be quite damaging for their brand, as a new Rakuten survey shows that email is the most popular customer service channel among online shoppers.

Around half (49%) of respondents said they prefer to use email compared to 43% on phone.

Rakuten’s stats are similar to findings from a survey we ran last year using Toluna. It revealed that 44% of UK consumers preferred email for customer service while one in three preferred telephone.