Zoho CPaaS does not support the following attachments as extensions:
ade, adp, bat, chm, cmd, com, cpl, exe, hta, ins, isp, js, jse, lib, lnk, mde, msc, msp, mst, pif, scr, sct, shb, sys, vb, vbe, vbs, vxd, wsc, wsf, wsh, app, asp, bas, cer, cnt, crt, csh, der, fxp, gadget, hlp, hpj, inf, ksh, mad, maf, mag, mam, maq, mar, mas, mat, mau, mav, maw, mda, mdb, mdt, mdw, mdz, msh, msh1, msh2, msh1xml, msh2xml, msi, msp, ops, osd, pcd, plg, prf, prg, pst, reg, scf, shs, ps1, ps1xml, ps2, ps2xml, psc1, psc2, tmp, url, vbp, vsmacros, vsw, ws, xnk
If you have any more questions, feel free to write to us at support@zohocpaas.com.