The six-month campaign, which is being handled by Abbott Mead Vickers BBDO, includes TV, radio, press and poster advertising, as well as an online push being handled by Social Republic, a division of the digital shop Agency Republic.
According to a statement from AMV, the campaign is designed to feel "non advertising. Like a guy telling his mate about the service rather than the Samaritans themselves. The ads echo the style of emails -- simple, uncluttered and informative."
Lines used in the creative, which is aimed at targeting 16- to 25-year-olds, include the question, "When was the last time anyone overheard an email."
The email service was launched by the charity two years ago but deals with just 3% of the overall contacts dealt with by Samaritans each year.
The service has the name jo@samaritans.org because the name is believed to be easily recognisable and give an identity to the person replying.
This latest campaign follows research carried out between July and September this year by NOP Research Group and The Dream Mill.
Samaritans chief executive David King said: "We know that one in four young people will suffer from depression and that sharing problems can help people to find a way forward.
"But there are many barriers to asking for help, from knowing who to ask, to feeling that it's OK to admit that things aren't going as well as they could.
"The research showed that simply having an awareness of our email service made young people more likely to feel that Samaritans is a good option if they want to discuss difficult issues in their life."
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