If you use Outlook Express 5.0 or higher, on occasions, you're likely to receive ATT files as email attachments. The anonymous file attachments usually have a .att extension. Files ATT000XX.txt or ATT000XX.htm can also appear as attachments in emails sent to your inbox. In some instances, an ATT attachment may appear in an email with a blank message. The ATT files are error files and do not carry any known viruses. However, it is advisable not to download these attachments.
The reasons are numerous why an ATT attachment may appear in an Outlook message. Email service providers such as Yahoo or Hotmail, have limits on the size and number of attachments an email may contain. If a sender attaches over-sized files to an email, the attachments may be stripped before the email reaches the receiver's inbox. Instead, when the receiver opens the email via Outlook, he may find ATT files as attachments.
Sometimes emails are sent in a HTML or RTF format, which support for information to be presented in a graphical interface. However if a receiver's email settings do not support such content, the graphic features of a HTML or RTF message are captured in an ATT file and the original message converted into a text format. Therefore, in an outlook template, the message may appear in plain text with a erroneous ATT file attached to the email.
ATT files may also appear in an Outlook message if an email is sent from an unrecognized server. Many organizations and offices use Outlook as a front-end interface for employees to send and receive business emails. Companies also set restrictions and filters to regulate incoming emails. So, if an email comes from an unrecognized server or a website, the incoming message may be filtered and attachments stripped before the email reaches the receiver's inbox. Further, one or more ATT files may instead appear as attachments.
One way to limit ATT attachments is to make sure the email settings allow for HTML and RTF formatted messages. Also, cleaning the inbox may help in creating space for new and incoming over-sized emails. Also, deleting temporary internet files and temp files from the cache may also help reduce the appearance of ATT files in Outlook messages.