From a security perspective, waimao.us tram Mail Server would reject inbound mails containing attachments with any of the following file extensions:
| 
 .ade  | 
 .adp  | 
 .adt  | 
 .app  | 
 .asd  | 
 .asp  | 
 .asx  | 
 .bas  | 
| 
 .bat  | 
 .bin  | 
 .btm  | 
 .cab  | 
 .cbl  | 
 .cbt  | 
 .cgi  | 
 .chm  | 
| 
 .cil  | 
 .cla  | 
 .clas  | 
 .class  | 
 .cmd  | 
 .cpe  | 
 .cpl  | 
 .crt  | 
| 
 .csc  | 
 .csh  | 
 .css  | 
 .cvp  | 
 .dll  | 
 .dot  | 
 .drv  | 
 .exe  | 
| 
 .fon  | 
 .fxp  | 
 .hlp  | 
 .hta  | 
 .htr  | 
 .inf  | 
 .ini  | 
 .inp  | 
| 
 .ins  | 
 .isp  | 
 .jar  | 
 .js  | 
 .jse  | 
 .keyreg  | 
 .ksh  | 
 .lib  | 
| 
 .lnk  | 
 .mda  | 
 .mdb  | 
 .mde  | 
 .mdt  | 
 .mdw  | 
 .mht  | 
 .mhtm  | 
| 
 .mhtml  | 
 .msc  | 
 .msi  | 
 .msp  | 
 .mst  | 
 .mp3  | 
 .nte  | 
 .nws  | 
| 
 .obj  | 
 .ocx  | 
 .ops  | 
 .ov  | 
 .pcd  | 
 .pgm  | 
 .pif  | 
 .pl  | 
| 
 .pm  | 
 .prg  | 
 .scr  | 
 .sct  | 
 .shb  | 
 .shs  | 
 .slb  | 
 .smm  | 
| 
 .swf  | 
 .swt  | 
 .sys  | 
 .vbe  | 
 .vbs  | 
 .vbx  | 
 .vir  | 
 .vmx  | 
| 
 .vxd  | 
 .wmd  | 
 .wms  | 
 .wmz  | 
 .wsc  | 
 .wsf  | 
 .wsh  | 
 .xms  | 
| 
 .com  | 
