Can you provide more information about the issue? * Do you mean that when you view the message in Thunderbird that you don't see that it has an attachment or that you don't see the message in your inbox at all? * Are you verifying that the message with the attachment is in the mail folder by checking the webmail portal? * What email provider are you using and are you connecting to them in Thunderbird via POP3 or IMAP? * Are you running any sort of security software that has an Antispam function? * Which operating system and version of Thunderbird are you using? The answers to these questions and any other pertinent information you think would be useful will better allow us to find the solution to your issue.