This is a difficult question to answer, as email newsletters can vary greatly in length and content. Some email newsletters are just a few lines long, while others may be several pages long. Ultimately, the length of an email newsletter will depend on the purpose it serves and the audience it is intended for. For instance, a newsletter that is meant to provide updates on a company's latest products or services will likely be shorter than one that is meant to provide detailed information about a particular topic. Additionally, email newsletters that are geared towards busy professionals may be shorter and more concise than those aimed at general audiences. Ultimately, it is up to the sender to determine the appropriate length for their email newsletter.