Applies to: Office 365 for enterprises, Live@edu
Topic Last Modified: 2011-11-23
In Exchange Online, Exchange Search (which is used by the Multi-Mailbox Search feature) includes default filters to index different types of files that may be attached to e-mail messages. The indexing of file attachments with these filters lets you search the content of attachments for keywords. Exchange Search also includes a safe list of file types that aren’t indexed because they don’t contain any indexable data.
- Unsearchable items If a file type doesn’t have a corresponding filter or if it isn’t indexed for any reason, a multi-mailbox search will fail for that file type. When you configure a multi-mailbox search, you can select the option Include item types that can’t be searched to include mailbox items in the search results that can’t be searched because their file format is unsearchable or for any other reason. For more information, see Include Unsearchable Items in the Search Results.
- Safe lists Certain file types aren’t indexed because they don't contain any indexable data. File types specified in the safe list aren't searched and aren't returned as unsearchable. Examples of these file types include Joint Photographic Expert Groups (JPEG) and Graphics Interchange Format (GIF) image files, and Windows Media Video (WMV) and Waveform Audio (WAV) media files.
The following table lists the file types that are indexed for Exchange Search.
| .ascx | .asm | .asp | .aspx | .bat | .c |
| .cmd | .cpp | .cxx | .def | .dic | .doc |
| .docx | .dot | .h | .hhc | .hpp | .htm |
| .html | .htw | .htx | .hxx | .ibq | .idl |
| .inc | .inf | .ini | .inx | .js | .log |
| .m3u | .mht | .odc | .one | .pl | .pot |
| .ppt | .pptx | .rc | .reg | .rtf | .stm |
| .txt | .url | .vbs | .wtx | .xlc | .xls |
| .xlsb | .xlsx | .xlt | .xml | .zip |
|
You can run the following Windows PowerShell command to display a list of file extensions that are indexed for search in Exchange Online.
Files types in the safe list aren’t indexed or searched because they don’t contain searchable data. As previously mentioned, file types specified in the safe list aren't returned as unsearchable. The following table includes the safe list file types.
| .3g2 | .3gp | .3gp2 | .3gpp | .AAC | .ADT |
| .ADTS | .aif | .aifc | .aiff | .asf | .asx |
| .au | .avi | .bmp | .dib | .DVR-MS | .emf |
| .gif | .ico | .IVF | .jfif | .jpe | .jpeg |
| .jpg | .m1v | .M2T | .M2TS | .M2V | .m4a |
| .m4b | .m4p | .m4v | .mid | .midi | .MOD |
| .mov | .mp2 | .mp2v | .mp3 | .mp4 | .mp4v |
| .mpa | .mpe | .mpeg | .mpg | .mpv2 | .MTS |
| .png | .rle | .rmi | .snd | .TS | .TTS |
| .vob | .wav | .wax | .wdp | .wm | .wma |
| .wmf | .wmv | .wmx | .wpl | .WTV | .WVX |
You can run the following Windows PowerShell command to display a list of file extensions in the safe list.
