Instituto Superior Técnico

Serviços de Informática

What types of files can be sent as attachments in e-mail?

The email servers from IST do not allow the distribution of email attachments that correspond to executable files, as these types of files are currently associated with the spread of malware. Thus:

  • All emails that include executable attachments with one of the following suffixes will be filtered: ade, adp, bas, bat, chm, cmd, com, cpl, crt, exe, hlp, hta, inf, ins, isp, js, jse, lnk, mdb, mde, msc, msi, msp, mst, pcd, pif, reg, scr, sct, shs, shb, vb, vbe, vbs, wsc, wmf, wsf, wsh, iso. Files whose name contains curly braces ( { } ) will also be filtered.
  • The list of attachments that are subjected to filtering does not include the file types commonly used in academic applications (such as MS Office documents, images, audio and video files, pdf, postscript and .zip, .tar, .tgz or .rar files) – Right now, all MS Office file types that contain Macros are filtered.
  • In the case of filtering attachments, the messages will not be delivered to the recipient, and the sender will be notified of this fact and the reason for the filtering performed.
  • If users intend to receive files of one of the filtered types by email, they must ask the sender to send these files inside a zip, rar or tgz file format. The resulting file will not be inspected by the filtering system and can be used to send files with any extension.