The legal framework concerning liability of communication intermediaries for defamation is under-conceptualised. The paper thus develops a holistic doctrinal approach to liability of speech intermediaries, such as Internet service providers (ISPs), booksellers and newspaper vendors, for defamation. It views intermediary liability for defamatory speech against the backdrop of communication theory and freedom of expression doctrine. If properly conceptualised, as suggested in this paper, the law of defamation can accommodate the cyberspace-specific legislation in Arts 12–15 of the e-commerce Directive and s 5 of the Defamation Act 2013, as well as the innocent dissemination defence in s 1 of the Defamation Act 1996, now to be read together with s 10 of the Defamation Act 2013. The paper establishes six tenets of intermediary liability for defamatory content. In particular, it argues that ‘publication’ is to be conceptualised as a merely factual requirement for defamation, whereas the defence of ‘innocent publication’, also known as ‘innocent dissemination’, is a fault-based concept. Communication intermediaries are thus to be considered ‘publishers’, even if they have a merely automatic role in the publication process, but they may avail themselves of the defence of ‘innocent publication’. This defence has to be applied in compliance with the human rights of the parties involved.