Blocked File Extensions Survey
A list of file extensions blocked by mail server administrators, in order of preference. If an administrator blocks/disables attachments with a listed file extension, the count was incremented by one.
| File Extension | # of Times Found |
| scr | 32 |
| bat | 31 |
| pif | 31 |
| com | 30 |
| exe | 30 |
| vbs | 30 |
| cmd | 23 |
| shs | 23 |
| vbe | 23 |
| hta | 22 |
| reg | 22 |
| jse | 21 |
| wsf | 21 |
| sct | 20 |
| wsh | 20 |
| chm | 19 |
| js | 19 |
| lnk | 18 |
| cpl | 17 |
| hlp | 17 |
| wsc | 17 |
| shb | 16 |
| vb | 15 |
| msi | 14 |
| msp | 14 |
| bas | 13 |
| crt | 13 |
| ins | 13 |
| isp | 13 |
| msc | 13 |
| mst | 13 |
| ade | 12 |
| adp | 12 |
| mdb | 12 |
| inf | 11 |
| mde | 11 |
| pcd | 11 |
| url | 11 |
| dll | 9 |
| app | 7 |
| eml | 7 |
| mda | 7 |
| ocx | 7 |
| mdt | 6 |
| mdw | 6 |
| mdz | 6 |
| sys | 6 |
| vxd | 6 |
| class | 5 |
| fxp | 5 |
| ini | 5 |
| mp3 | 5 |
| ops | 5 |
| prf | 5 |
| prg | 5 |
| scf | 5 |
| xsl | 5 |
| zip | 5 |
| avi | 4 |
| bin | 4 |
| doc | 4 |
| mpg | 4 |
| asp | 3 |
| csh | 3 |
| drv | 3 |
| htm | 3 |
| ksh | 3 |
| mp2 | 3 |
| mpeg | 3 |
| wav | 3 |
| 386 | 2 |
| adt | 2 |
| asf | 2 |
| asx | 2 |
| cbt | 2 |
| ceo | 2 |
| css | 2 |
| gxe | 2 |
| html | 2 |
| js? | 2 |
| lib | 2 |
| mid | 2 |
| midi | 2 |
| mov | 2 |
| msg | 2 |
| mso | 2 |
| ov? | 2 |
| pot | 2 |
| smm | 2 |
| swf | 2 |
| tar | 2 |
| vba | 2 |
| xls | 2 |
| ?_ | 1 |
| {* | 1 |
| 00? | 1 |
| a | 1 |
| acm | 1 |
| arc | 1 |
| arj | 1 |
| asd | 1 |
| ax? | 1 |
| bif | 1 |
| bmp | 1 |
| bo? | 1 |
| btm | 1 |
| cab | 1 |
| cdr | 1 |
| cgi | 1 |
| cnv | 1 |
| csc | 1 |
| dat | 1 |
| dbx | 1 |
| dev | 1 |
| dl? | 1 |
| dldr | 1 |
| email | 1 |
| enc | 1 |
| fon | 1 |
| foo | 1 |
| gif | 1 |
| gms | 1 |
| gz? | 1 |
| hct | 1 |
| hto | 1 |
| htr | 1 |
| ice | 1 |
| im? | 1 |
| jar | 1 |
| java | 1 |
| jpe | 1 |
| jpg | 1 |
| lzh | 1 |
| mb? | 1 |
| md? | 1 |
| mht | 1 |
| mpd | 1 |
| mpp | 1 |
| mpt | 1 |
| mse | 1 |
| msm | 1 |
| mtx | 1 |
| nws | 1 |
| obd | 1 |
| obj | 1 |
| obt | 1 |
| ole | 1 |
| ovl | 1 |
| pcd | 1 |
| pci | 1 |
| pgm | 1 |
| php | 1 |
| pi | 1 |
| pl | 1 |
| png | 1 |
| qa? | 1 |
| qlb | 1 |
| qpw | 1 |
| rar | 1 |
| scx | 1 |
| sea | 1 |
| shm | 1 |
| sht | 1 |
| spl | 1 |
| sss | 1 |
| td0 | 1 |
| tgz | 1 |
| tlb | 1 |
| tsp | 1 |
| txt | 1 |
| uue | 1 |
| vcs | 1 |
| vs? | 1 |
| vwp | 1 |
| wab | 1 |
| wbk | 1 |
| wfc | 1 |
| wff | 1 |
| wfh | 1 |
| wiz | 1 |
| wmd | 1 |
| wms | 1 |
| wmz | 1 |
| wse | 1 |
| wsi | 1 |
| wss | 1 |
| xlv | 1 |
| xtp | 1 |
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