A survey has found that one in five people use a network out-bound service to manage their email and other digital files, and that many of them use it for email attachments.
The survey by research firm Ipsos Mori found that 56 per cent of respondents used an outbound email service for email files in the past year.
The average email attachment size was 728kb, the survey found.
A recent survey by analytics firm Comscore found that the average user spends up to seven minutes per day on an email account.
A user with a personal email account of at least 200 emails has a combined total of 9,700 contacts.
Some email users are also sending an average of more than a million emails a month.
“The trend towards outbound and personal email accounts is in large part driven by a desire to manage emails in their home environments, as well as a desire for personalization,” the survey said.
“These are often times highly personal attachments with attachments that are designed to be personalised and customized to match a particular user’s interests.”
The survey also found that a third of respondents said they use the service in a way that is inappropriate for their workplace.
The vast majority of email users surveyed said they did not know how to delete the attachments.
Some users, like email administrator Alex Poulson, have used the service to make sure that they never lose emails in case of a disaster.
“I use the ‘outbound’ email service a lot because it’s my primary email and the default way of getting emails from people,” Mr Poulsen told The Register.
“If I don’t want to have to deal with them, then I use the personal email option.”
The research also found some people may be using an out-of-band email service to get email from people outside their email addresses.
“This is a common situation when people who use the email address do not have a primary email address,” the research found.
“They send their outbound message and receive their response from the outbound server, but the out-mail server doesn’t have the primary address.”
Mr Poulsson said the use of the email outbound provider in this way was also a sign that people were choosing to use the services out of the expectation that it would be more secure.
“It’s like the old adage ‘you never know who might be watching’,” he said.
The survey found that 57 per cent were using the outbargaining service to keep up with the ever-increasing pace of email usage.
About two-thirds of respondents reported that they had used email outsourcing providers to manage email in the last year, with an average email delivery time of 1.6 hours.
Email providers, which are typically outsourced from other companies, often do not provide any privacy protection for emails sent from their systems, the research said.
The data also found there was an “increasingly positive relationship” between the use and retention of email.
The poll found that 47 per cent had been using email outbarge services in the previous 12 months.
“Outbound email and outsourcing can be beneficial to email users, but there is also a growing perception that these services do not offer as much protection as email providers,” the Ipsos survey found, and it was suggested that some providers might not be as secure as others.
Email outbound providers have been criticised in the UK in the wake of the Paris attacks.
In the wake, the UK government has called for “the creation of a new type of protected service provider to enable UK users to protect their emails”, but in March, the government announced it would cease the use.
In an article for the Mail on Sunday, the BBC reported that the use was growing, with “at least 10 per cent” of the UK population using email outsourcing services.
It said the survey showed that the majority of outbound customers were using outbound platforms for email delivery, but a further 15 per cent reported that their personal email was being accessed by an outbarger provider.
One of the biggest problems that people have in using email, according to Ipsos’ research, is the lack of privacy.
The research found that email out-bargains had been found to be “particularly susceptible to surveillance by law enforcement agencies”.
“Email outsourcing providers have come under particular scrutiny in recent years due to concerns over their security and privacy, particularly for the data that is sent and received,” Ipsos said.