The study by UK researchers also found that more than two-thirds of men who contacted had erection problems, which were frequently linked to loss of sex drive.
People can contact the UK-based Sexual Advice Association by telephone or email and talk to a chartered psychologist.
They also looked at the 5,531 telephone calls and 2,160 emails received during 2009 and 2010, with specific reference to the 673 emails that required a more in-depth reply from a doctor specialising in male sexual dysfunction.
"A lot of men do not seek medical advice for sexual problems and it is estimated that only half of them will seek help within a year," said lead author and family doctor Dr John Tomlinson, who ran a hospital-based men's health clinic for nine years and now works with the Sexual Advice Association.
"Although there have been a number of reports in the literature about the value of telephone helplines, little is known about the role of email advice in supporting patients with sexual problems," he stated.
An analysis of the 673 emails that required an in-depth reply showed that 71 percent were from the UK, 23 percent were from outside the UK and the rest were unknown.
Men aged 21 to 30 were most likely to make contact by email, accounting for a quarter of those received.
The most common problems were erection problems (69 percent), loss of sex drive (17 percent), premature ejaculation (12 percent), masturbation problems (10 percent) and genital problems (12 percent).
Erection problems increased with age and the age groups most concerned with premature ejaculation and lack of sex drive were 31 to 40 years and 41 to 50 years respectively.
The findings will be published in the October issue of IJCP, the International Journal of Clinical Practice.