Exclaimer has published research on trust in business email among US adults. The survey found that 36% of respondents have questioned whether a message they received was genuine.
The study of 1,000 people also found that 14% do not trust emails from external companies at all, as artificial intelligence becomes more common in day-to-day communications.
According to the findings, 65% of US adults now use AI in some part of their communications. The most common uses are improving grammar and spelling, cited by 20%, and making writing sound more professional, cited by 19%.
Other responses suggest AI is also being used to shape tone and personal presentation. Sixteen per cent said they use AI to sound more confident, 12% use it to soften difficult messages, 10% use it to avoid awkward conversations, and 9% use it to hide uncertainty.
Those figures point to a shift in how recipients judge business email. If a polished message can be produced or refined by software, the writing itself may carry less weight as a signal of who sent it and how much authority they hold.
Trust signals
Recipients focus on visible markers of identity when deciding whether a company email is credible. Full contact details were cited by 40% of respondents as a trust signal, followed by a professional email address on a company domain at 35% and a clear sender name at 30%.
Nearly one in four respondents, or 23%, said a professional, branded email signature makes a company email feel more trustworthy. That put it ahead of legal disclaimers at 17% and consistent formatting at 16%.
The findings suggest design and identity cues are becoming more important as people assess whether a message is legitimate. A company domain, a named sender and contact information appear to matter more than generic presentation features.
Laura Wilkinson, Vice President of Global Marketing at Exclaimer, said: "The findings show that AI isn't reducing the importance of trust in business communications but changing how people establish it. When anyone can generate a polished, professional email in seconds, recipients look beyond the words for proof that a message is genuine. For businesses, email governance is more important than ever. Trust comes from giving every email a clear, verifiable identity that customers, employees and partners can recognise and rely on."
Email's role
The survey also points to email retaining a central role in formal and durable communication. Thirty-five per cent said it is their preferred channel for employer updates, while 33% chose it for formal complaints to a company and 27% for healthcare information.
Its value appears closely tied to record-keeping. When respondents need information they can keep or refer back to, 43% said they choose email, and 33% said they have deliberately used email instead of another channel because they wanted a permanent record.
That preference may help explain why concerns about authenticity carry wider implications for companies. If email remains the channel people rely on for formal exchanges and information retention, doubts about who sent a message could affect customer communication, employee updates and service interactions.
Channel effect
The platform used for communication also shapes perceptions, according to the data. Forty-three per cent of respondents said the channel affects how trustworthy a communication feels, while 39% said it shapes their view of its professionalism and authenticity.
For companies, that means email presentation is not just a matter of style. The details attached to a message, including sender name, company information, contact details and signature, can influence whether recipients regard it as genuine.
The findings suggest organisations need tighter control over how sender identity is displayed across email traffic, rather than relying only on secure domains or well-written content. Exclaimer, which sells email signature management software for Microsoft 365 and Google Workspace, said the issue is becoming more pressing as AI makes it easier to produce convincing messages at scale.
The business says it is used by more than 9 million users across 85,000 organisations worldwide, including Sony, Mattel, Bank of America, NBC, the Government of Canada, the BBC and the Academy Awards.