A text, video, graphic, PDF or sound file that accompanies an email message but is not included in the message itself. Attachments are not a good way to send email newsletters because many ISPs, email clients and individual email recipients do not allow attachments, because hackers use them to deliver viruses and other malicious code.
![Laptop computer with emails list on screen. 3d illustration](https://cdn.igeniushost.com/sendoffice/images/laptop-computer-with-emails-list-on-screen-3d-illustration-wpp1671217365990-754x583.jpg.webp)
3 Quick And Easy Ways To Build A Profitable Opt-In List
You finally realize that you need a good opt-in list. After reading countless articles and sought expert advices and have read many success stories of people creating a small fortune with opt-in lists you finally decide to have one of your own.